Hawk Talk

[Ariel Red Hunter]

This is a commentary on what I have noticed about the Hawk. It has sold very well, which is good for potential riders, reducing potential parts problems. And a large history of success in the hands of riders. Most people are very happy with their Hawks, but some have had minor problems. Now to the nittie-gritti. The engine is a very good one, originally made for Honda in China. It was originally a 125 or 150, so expanding it to 229cc is about as far as they can go. It is a pushrod single with a short stroke, which means it can sustain high rpm's without valve float, because the pushrods are very short and light. Caged ball main bearings with a roller bearing crankpin. It does not have a crankshaft counter-balancer shaft, although 250's really don't need balancer shafts. The plus on this engine for you is that the non balance shaft engines have a gear drive oil pump. The counter-balanced engines have a chain driven oil pump. Gear drive primary to the clutch and transmission, which is a five speed. Final drive is by 428 chain. The quality of the final drive chain is suspect. Another problem is in the quality of the fluids used on the bike. I would change the engine/transmission oil before I even started it for the first time to some high quality American 15W-40 oil. I would also clean the brake rotors with brake cleaner before I rode it for the first time. The brake fluid is also suspect. Change it out to an American/Canadian DOT 3 or 4 brake fluid. If, after a couple hundred miles, the front forks are not damped well enough, change that out too. People have reported good luck using ATF in the forks. Well that's enough for now. Later we will get into carburation an exhaust issues, and drive chain suggestions.

[chuck]

This is a commentary on what I have noticed about the Hawk. It has sold very well, which is good for potential riders, reducing potential parts problems. And a large history of success in the hands of riders. Most people are very happy with their Hawks, but some have had minor problems. Now to the nittie-gritti. The engine is a very good one, originally made for Honda in China. It was originally a 125 or 150, so expanding it to 229cc is about as far as they can go. It is a pushrod single with a short stroke, which means it can sustain high rpm's without valve float, because the pushrods are very short and light. Caged ball main bearings with a roller bearing crankpin. It does not have a crankshaft counter-balancer shaft, although 250's really don't need balancer shafts. The plus on this engine for you is that the non balance shaft engines have a gear drive oil pump. The counter-balanced engines have a chain driven oil pump. Gear drive primary to the clutch and transmission, which is a five speed. Final drive is by 428 chain. The quality of the final drive chain is suspect. Another problem is in the quality of the fluids used on the bike. I would change the engine/transmission oil before I even started it for the first time to some high quality American 15W-40 oil. I would also clean the brake rotors with brake cleaner before I rode it for the first time. The brake fluid is also suspect. Change it out to an American/Canadian DOT 3 or 4 brake fluid. If, after a couple hundred miles, the front forks are not damped well enough, change that out too. People have reported good luck using ATF in the forks. Well that's enough for now. Later we will get into carburation an exhaust issues, and drive chain suggestions.
Great job Ariel Red Hunter. I have been waiting for an article like this regarding the engine,now I feel a lot better when I hold the throttle open.I have been very impressed so far with the quality of the bike being my first chinese bike.More info will be appreciated.

[jet321]

Good write up Red. I feel the same about the hawk, it's definitely an econo bike. It's cheap fun honestly, you can go anywhere with that little bike. There's issues here and there, but a lot of them can be avoided if you're the first time owner and set it up properly.

[Ariel Red Hunter]

Great job Ariel Red Hunter. I have been waiting for an article like this regarding the engine,now I feel a lot better when I hold the throttle open.I have been very impressed so far with the quality of the bike being my first chinese bike.More info will be appreciated.
Yes, it is a superb little engine, almost perfect for its role in the Hawk. A wide mid-range that is what you need off road, and this engine has it. But it can be improved. The jetting in the carburetor is way too lean, the exhaust system reminds me of what a top engine tuner described the problem with my AJS 350. "It inhales really well, but it suffers from constipation on the exhaust side". The head pipe of the exhaust is awful - not to even mention the catalytic strangler that is in there. Even if you remove the cat, the poor flow at the very beginning of the head pipe and the gasket between the port and the head pipe are pretty bad. I personally would change the carburetor out for a Mikuni VM 26 (So much easier to re-jet), and buy and install a complete new after market exhaust system, not forgetting to use that Honda copper o-ring gasket next to the exhaust port. When riding off road, having an exhaust you can hear is much more useful than having a tachometer. I think the Magician is a considerably better on-road bike, a tach on the Magician would serve as something besides an ornament. Modifying the air box for more flow helps also. Moto-cheez has a youtube video showing how to do it.

[pete]

The push rods are light but still have mass that is traveling in a
linar motion and has to be stoped then returned in the oppisite direction..
A over head cam shaft dose have a lot more mass but is dynamic & dose not require
stoping to change direction like push rods..


..

[Bruce's]

What have you done to the head pipe on yours Ariel ?did you find something that works off the shelf or build your own ?

[2LZ]

Good write-up. I've had both versions now of the venerable CG motor. The balanced shaft is definitely more smooth across the RPM range, though the non-balanced motor is more simple with less parts. You can't go wrong with either version.

The Hawk is by far the "best 2 wheeled bang for the buck" on the planet (Storm is right there as well if you can get one). I'd say the biggest issue that the Hawk has is that RPS doesn't seem to be in a big rush to spend the $$$ to get it DOT approval.

Coming from CA, I can see that jumping through the CARB hoops is a hassle...but to ship these everywhere leaving it to "buyer beware" regarding street registration in most states is quite undesirable. If RPS would get this straightened out, they'd sell even tons more than they do now.

As Adam quoted: "Note that the Magician (like the Hawk) is not a DOT motorcycle and on-road registration is dependent upon your local DMV. There is a long-term plan to make both bikes DOT compliant, but there is a lot of bureaucracy involved with that."

This needs to be fixed. To me, it's the only real problem, even if they never do become available here in CA. 49 other states will be quite happy.

[Adam Rinkleff]

to ship these everywhere leaving it to "buyer beware" regarding street registration in most states is quite undesirable.

We don't actually sell to users. We sell to dealers, inform them of its status, and the dealers assure us that they know where they can and can't sell it. New customers who want it on-road need to ask the dealer if they can register it.

Some dealers are better than others. Some sell into states where they do not have an active license, which doesn't help. If your dealer doesn't guarantee registration, you should be wary. If a dealer says that they can get it on-road in any state, they are lying.

That said, there is a long-term plan to get DOT compliance, but it will require retooling at the factory. Since China would be spending funds solely for the US market, they won't do it unless they are convinced there is sufficient demand. Right now, the Hawk is doing well, so they are gradually improving it.

You do get what you pay for. The Hawk is relatively cheap, but it's not a bonafide motorcycle. We could easily fix the carb issue for California, but that would also increase the cost of the bike. Fortunately, we are going to be importing Lifan Motorcycles, and those will be better (and more expensive).

[Adam Rinkleff]

Another problem is in the quality of the fluids used on the bike. I would change the engine/transmission oil before I even started it for the first time

Yes, we recommend flushing the fluids. They are not intended for use, the fluids are in there to keep components from rusting/etc as it takes months to ship them across the Pacific.

[2LZ]

You do get what you pay for. The Hawk is relatively cheap, but it's not a bonafide motorcycle. We could easily fix the carb issue for California, but that would also increase the cost of the bike. Fortunately, we are going to be importing Lifan Motorcycles, and those will be better (and more expensive).
Thanks for the response Adam. Being a CA native, I don't blame those who don't want to play the CARB game ($$$). It's strict and that's why there are only two available CB's here. The CSC TT250 and the SSR XF250. It's just the way it is and we're used to it.

It's the rest of the states that really should be dealt with though. CA is a HUGE market...but so are 49 others. I'm not sure what retooling may need to occur. Most other states don't require the smog pump and purge can to be road legal, as they do here in CA.

It will be interesting to watch and see how this unfolds. Keep us in the loop on any new news, please.

[Ariel Red Hunter]

What have you done to the head pipe on yours Ariel ?did you find something that works off the shelf or build your own ?
I haven't bought a Hawk. I am getting close to 80 years old. I'm not sure a motorcycle is a good idea at my age. What I type up here is a production engineers view of them. I hunt for information on stuff, then analyze it. You are reading the results of my studies. And the results of my experience. I've been riding since 1951. But I will tell you this; if I was going to buy a motorcycle this year, it would be a HAWK!! :p

[Ariel Red Hunter]

Yes, we recommend flushing the fluids. They are not intended for use, the fluids are in there to keep components from rusting/etc as it takes months to ship them across the Pacific.
Adam, I'm glad you brought that up. It is a long way from here to China. People, think about all of those enviornmental heating and cooling cycles these bikes go through before they even get to our shores. Everyone of those cycles can cause condensation. In other words, the oil, grease and brake fluid has contamination in them long before they get here. Protect your investment by changing all of the fluids and grease as part of the assembly process. You'll end up a lot happier.

[Ariel Red Hunter]

The push rods are light but still have mass that is traveling in a
linar motion and has to be stoped then returned in the oppisite direction..
A over head cam shaft dose have a lot more mass but is dynamic & dose not require
stoping to change direction like push rods..


..
What you say is true. And on a street engine it is important. And of course, racing engines. As to the advantages of an overhead cam engine for a dual-sport/enduro, my experience is that they are over rated. What is needed is low-mid range grunt, which is easy to get with overhead valves. It would be just as easy to get with an overhead cam engine, if it was designed to the same protocal. But they are not. They are designed to take advantage of their lighter valve gear at high rpms. And their power curve reflects this. I used to be involved in road racing, after my time playing with 500 Goldstars on American flat tracks. The AMA changed the rules (from 500 overheads vs 750 flatheads to 750 overheads),so I lost interest. I was a great believer in the advantages of overhead cam engines, so I bought a 250 Ducati. Did fairly well for a while until I got my plow cleaned by Moto Parilla's and Aermacci Harley Davidsons. Both of those 250's were pushrod OHV engines. The real advantage of overhead cam engines comes at 350cc and bigger, for road racing.

[Ariel Red Hunter]

Part two was supposed to be chassis run through, but not so. Your poor scribe has been called out to defend the humble, but useful, pushrod OHV 229.9 cc HonChi engine. This engine has been compared to OHC engines, and crankshaft balance shaft engines. And it has been found wanting. So let's look more closely at this engines plusses and minuses. It has plenty of both. At least from my point of view. Plusses: air-cooled. Simple. Light in weight. Less expensive to produce. Unit construction (engine and gearbox in one set of cases). Because it is a pushrod engine, more weight is low, in the cases. It has some kind of gee whizz electronic ignition. It is relatively light in weight. It is relatively easy to do valve adjustments on. It responds very well to exhaust and carburetor upgrades. Minuses: It doesn't have a balancer shaft. It doesn't have an overhead cam. It only holds about 35 ounces of lube oil. Lube oil also used for transmission. So this engine is almost perfectly suited for an inexpensive off road dual sport at the low end of the price spectrum. It is much less qualified to be an engine in a bike that is primarily used on pavement. It does not have the top end for that job. I'm sure it can be modified for more top end, but if you do that you will lose out on the bottom end and midrange. The Magician and the TT250 are better suited for on highway use. I don't like the Magician because it has a 16" rear wheel. I don't like the TT250 because it costs a lot more than the Magician, or Hawk. The Magician and Hawk are the bottom feeders in the 250 class. The Magician is a nice 90% 10% on-road off-road bike. The Hawk is a very nice off-road bike that is street legal, at least in many states. Perfect for riding 10-20 miles to the dirt trails you want to ride all day. If you stay off the interstates with it. Bottom line: you can have a lot of fun on a Hawk for short money.

[Darkrider]

Should add...can have a lot of fun with the Hawk if you can get it where you live lol

[Ariel Red Hunter]

An overhead cam engine. Hmm. there are trade-offs, as always. Engine is almost always taller. (Except certain weird designs, like the face-cam Chater-Lea). Very difficult to make as light as a push-rod job. If it is a chain drive, should have a 50% reduction to the chain. That way the chain runs at half of engine speed. For a racing engine, with the best parts obtainable, built virtually without regard to cost, taking the reduction in the chain drive system is acceptable because of less weight. We now live in the age of total mass-production. So an engine is now designed for a purpose, not just as a lightweight, junior, or senior class. Road bikes are the most popular class. So an engine is usually designed for a roadster, where acceleration and top speed is very important, especially in the lightweight class (250cc). Then, if the powers that be decide an enduro/dual sport is required to fill out the line, it should be no surprise that they look at the engine they are already building, for reasons of cost control. Perhaps they design a more tractable cam and fit a smaller carburetor. But the porting stays the same, which is really too big for an off-road bike engine. Of course, when cost is no object, then we have bikes like the KTM.

[2LZ]

An overhead cam engine. Hmm. there are trade-offs, as always. Engine is almost always taller. (Except certain weird designs, like the face-cam Chater-Lea). Very difficult to make as light as a push-rod job. If it is a chain drive, should have a 50% reduction to the chain. That way the chain runs at half of engine speed. For a racing engine, with the best parts obtainable, built virtually without regard to cost, taking the reduction in the chain drive system is acceptable because of less weight. We now live in the age of total mass-production. So an engine is now designed for a purpose, not just as a lightweight, junior, or senior class. Road bikes are the most popular class. So an engine is usually designed for a roadster, where acceleration and top speed is very important, especially in the lightweight class (250cc). Then, if the powers that be decide an enduro/dual sport is required to fill out the line, it should be no surprise that they look at the engine they are already building, for reasons of cost control. Perhaps they design a more tractable cam and fit a smaller carburetor. But the porting stays the same, which is really too big for an off-road bike engine. Of course, when cost is no object, then we have bikes like the KTM.

Good points and it has to do with riding need and preference.

The absolute beauty of the CG motor, both balanced and unbalanced, is that it's built to be bullet proof under the worst conditions possible. It's all about simplicity, ease of repair and long term reliability. Thanks to the pushrods, it does have a really nice mid-range that's a very useful, utilitarian powerband. It also sips gas. Another plus.

For instance, my neighbor has ridden my Q multiple times now. Granted, it's just a 200cc but it's an OHC Suzuki-type motor, a real Mikuni CV carb and it develops much more top end than the TT, even modified. I have it geared longer legged because the top end will pull the higher speeds. Q can pull 70 mph. Ridiculous for a little 200cc bike.

Then he rode the TT... His quote was "This is exactly what I'm looking for in a 250. More torque and useable power for our hills, dirt roads and curves." He really liked the power band and the friendly attitude of the CG motor.

These motors, while mod-able to get their true potential, need to be seen as what they really are. Simple, low maintenance, with long term reliability and user friendly power...that can haul your family of three and a goat to slaughter....on very little fuel.

[BlackBike]

Good points and it has to do with riding need and preference.

The absolute beauty of the CG motor, both balanced and unbalanced, is that it's built to be bullet proof under the worst conditions possible. It's all about simplicity, ease of repair and long term reliability. Thanks to the pushrods, it does have a really nice mid-range that's a very useful, utilitarian powerband. It also sips gas. Another plus.

For instance, my neighbor has ridden my Q multiple times now. Granted, it's just a 200cc but it's an OHC Suzuki-type motor, a real Mikuni CV carb and it develops much more top end than the TT, even modified. I have it geared longer legged because the top end will pull the higher speeds. Q can pull 70 mph. Ridiculous for a little 200cc bike.

Then he rode the TT... His quote was "This is exactly what I'm looking for in a 250. More torque and useable power for our hills, dirt roads and curves." He really liked the power band and the friendly attitude of the CG motor.

These motors, while mod-able to get their true potential, need to be seen as what they really are. Simple, low maintenance, with long term reliability and user friendly power...that can haul your family of three and a goat to slaughter....on very little fuel.

Hehe good read, just like you knew what you were doing.

[Ariel Red Hunter]

Someone asked me about my riding experience. I think I will start by telling you all the motorcycles I have owned, or had considerable experience with. First bike was a Francis-Barnett 125. Three speeds. Slow, slower, and damn near stopped. Topped out at just over 40 mph. Then I finagled my way into the ownership of an Ariel Red Hunter 350. Wonderful bike. Had good tele hydraulic front forks, and Antsey Link rear suspension. Came with a well tuned engine, like all Red Hunters. Wonderful handling, and beautifully built. 1949 year model. Had a Lycette saddle. Topped out at about 84 mph. Rode my first TT race on it. (Southern California TT's). Then a 350 AJS. Why? It had SwingArm rear suspension. The engine wasn't as powerful as the Ariel, but the swing arm rear meant the rear wheel was "hooked up" more of the time on the TT tracks, so it was actually faster around the course. It also jumped better. 3.50X19 front and rear. I ran a Pirelli Universal on the front, and a Goodyear Grasshopper on the rear. I did pretty well with that bike, usually finishing in the top 4. I was considered crazy because I used the front brake. Then there was a short romance with a H-D 74. It was a good highway bike, but a hard starter. Then I lucked into a 1938 Indian Chief that had been brought up to Bonneville specs. 80 cubic inches. Would really stroll. Ate H-D 74's for breakfast. Mucho fun.

[hertz9753]

I bought a K&N 33-2238 filter that somebody was talking about here. It is smaller than stock but it does fit. The sound reminds me of flipping the lid on a round air cleaner in an old car. Not that I ever did that..

[2LZ]

Awesome drop-in hertz! I think I remembered someone saying they greased the gasket edge or something like that? Did you have to do that?

[hertz9753]

Awesome drop-in hertz! I think I remembered someone saying they greased the gasket edge or something like that? Did you have to do that?

https://www.amazon.com/Duck-282435-Heavy-Duty-Adhesive-Weatherstrip/dp/B0025KUSXW

Since the lip wasn't as thick as stock I used that on the top and grease on the bottom.

I never just buy what I came for when I go to Runnings. I also think that blonde chick in the water trough wanted to go home with me. :tup:

[BlackBike]

https://www.amazon.com/Duck-282435-Heavy-Duty-Adhesive-Weatherstrip/dp/B0025KUSXW

Since the lip wasn't as thick as stock I used that on the top and grease on the bottom.

I never just buy what I came for when I go to Runnings. I also think that blonde chick in the water trough wanted to go home with me. :tup:

Or stab you in the kidney at the first stop and rob your arse. Ain't I nice :hi:

[Ariel Red Hunter]

Someone asked me about my riding experience. I think I will start by telling you all the motorcycles I have owned, or had considerable experience with. First bike was a Francis-Barnett 125. Three speeds. Slow, slower, and damn near stopped. Topped out at just over 40 mph. Then I finagled my way into the ownership of an Ariel Red Hunter 350. Wonderful bike. Had good tele hydraulic front forks, and Antsey Link rear suspension. Came with a well tuned engine, like all Red Hunters. Wonderful handling, and beautifully built. 1949 year model. Had a Lycette saddle. Topped out at about 84 mph. Rode my first TT race on it. (Southern California TT's). Then a 350 AJS. Why? It had SwingArm rear suspension. The engine wasn't as powerful as the Ariel, but the swing arm rear meant the rear wheel was "hooked up" more of the time on the TT tracks, so it was actually faster around the course. It also jumped better. 3.50X19 front and rear. I ran a Pirelli Universal on the front, and a Goodyear Grasshopper on the rear. I did pretty well with that bike, usually finishing in the top 4. I was considered crazy because I used the front brake. Then there was a short romance with a H-D 74. It was a good highway bike, but a hard starter. Then I lucked into a 1938 Indian Chief that had been brought up to Bonneville specs. 80 cubic inches. Would really stroll. Ate H-D 74's for breakfast. Mucho fun.
And it had that strange (to modern eyes) leaf spring front suspension. You guys would be amazed at how well that front suspension worked. And how beautifully it steered. That year was either the last or next to last year Indian Chief with 18" tires, front and rear. I bought that bike for $400.00. Check what they bring now. I sold the Indian in order to buy a pick-up so I could haul a BSA Goldstar flat tracker back and forth. I wasn't good enough to compete in that league, so other people rode it. 60-40 split. Bike owner got 60% of the winnings. That bike was too expensive for me to keep competitive, so I sold it and bought a 250 Ducati bevel drive single for road racing. Did OK with it until the Moto-Parilla's and the Aermacci Harley-Davidsons started to show up. Those were both push rod singles, and were considerably faster than the Ducati's. I eased out of road racing when the Yamaha strokers started to come on. I didn't have a bike for a couple of years (I was involved with an Offy powered sprint car.) so I bought an AJS Model 14 CSR. That's a 250, and a very fast (and Light) one. Eventually, after I got married, I had a BSA Thunderbolt 650, then a Triumph 500 along with a Triumph Trophy 250. A couple of more years went by, then a Honda XL 125 (one of the hardest starting bikes I've ever owned) but fun to ride, a BMW R90S and that's about it. Oh yeah, a Yamaha DT175 and an iron head Sportster.

[hertz9753]

Or stab you in the kidney at the first stop and rob your arse. Ain't I nice :hi:

I don't think they can hold a knife.

[BlackBike]

Delicious, nice work with weatherstripping.

[LunaTech]

@hertz9753-I did the same thing except I used some black sticky back weather stripping I had. Worked great sealing it up. The K&N rubber seal area is just a little thinner than the stock.

[Ariel Red Hunter]

One of the charms, generaly speaking, of 250 cc motor-cycles, is you can enjoy riding them really hard without annoying the minions of the law. Also depends on which state you live in, of course. Vermont has a 45 mph limit on two lane roads, Texas has a 70 mph limit on their 2 lanes, out in the country.

Now, back to the Hawk. I would immediatly change the engine oil to a 15W-40, or 20W50 before I even started it up. I use Shell Rotella because it is easy to get. I would run dino oil for the first 500 miles, then change it to synthetic. Synthetic deals with the heat these engines produce better, and lasts longer. It also deals with lubing the transmission better, because it withstands the slicing and dicing going on in the transmission better as well. Then I'd change the oil every 1000 miles. Oil really takes a beating in this engine, partly because there isn't very much of it.
Old timey trick is to smear grease over the inside of the air-cleaner box (not on the element!). Captures sand and other grit going in the box. What to do about carburetion and exhaust is up to you. I would change to a VM26 Mikuni, the one with a starting circuit instead of a butterfly choke. I would change the exhaust system completely. The stock head pipe is the worst I have ever seen for exhaust flow. Also change the gasket where the head pipe meets the head to the copper o-ring type. These engines seem to respond really well to changing the spark plug to the Iradium type. Be sure to check the valve adjustment. They seem to come from the factory over tight.

[hertz9753]

I bought the cheap 'fake' one carb.

[hertz9753]

@hertz9753-I did the same thing except I used some black sticky back weather stripping I had. Worked great sealing it up. The K&N rubber seal area is just a little thinner than the stock.

You are that guy. Only two of us have tried the tried the K&N so far.

The weather stripping is used so the retainer can push down on the filter and the filter seals on the airbox. :tup:

[LunaTech]

You are that guy. Only two of us have tried the tried the K&N so far.

The weather stripping is used so the retainer can push down on the filter and the filter seals on the airbox. :tup:

Yep, I just used the square stick on weather stripping on mine. Great minds think alike ;)

[Ariel Red Hunter]

A word about single lobe cams and valve timing. Because the engine uses only one cam lobe does not mean that valve timing has to be concentric, e.g. 20-70 70-20. It depends on the shape of the valve lifter foot, and the location of the lifter shaft. For example, My Ariel Red Hunter had timing of 18-68 & 63-23. For those few of you who don't know what that means, it is inlet opens before TDC, inlet closes after BDC & exhaust opens before BDC, and exhaust closes after TDC. Just plug the numbers in, and you will know. I've not, so far, found a valve timing diagram for this neat little engine. If someone knows, share it with the rest of us. Timing should be a little bit more radical for the Hawk engine because peak power is at 7500 rpm. My NH (350) Red Hunter peaked at 6250 rpm.
The chassis: The Hawk has a rugged steel frame, with a 3.00 X 21 inch front wheel and tire, and a 4.10 X 18 rear wheel & tire. They have disc brakes front and rear. For whatever that's worth. In my opinion, not much, on a primarily off-road bike. They have quite good, but not the ultimate, front forks. You can improve front fork damping by changing the oil in the forks out to Dexron ATF. If you want even more damping, use Ford type Mercon ATF. On the question of the rear shock, a reservoir type shock is easier to change the damping on. Watch the swing arm bushings carefully, some of them have disintegrated in short order. If it was my bike, when they go, I'd change to urethane bushes. If I was real fussy, I'd change to bronze oilite bushings. Oilite bushings really tighten up the handling. Depends on how fussy you are.

[chuck]

You just answered my swingarm dilemma,mine was bone dry when I took it apart,I greased it all up, let's see how long it will last before I have to replace the bushings.I noticed some wear with only 700 miles on the bike.

[Ichrisbot]

My swingarm bushings were absolutely pulverized, fell apart like dust when I took the rear apart. They were bone dry as well, although I did do nothing but hard off roading with the bike up until that point.

[Ariel Red Hunter]

My swingarm bushings were absolutely pulverized, fell apart like dust when I took the rear apart. They were bone dry as well, although I did do nothing but hard off roading with the bike up until that point.
I've heard that before. The bushing is supposed to be vulcanized to the inner metal tube, and press fitted into the outer tube I think. What did you replace them with?

[Ariel Red Hunter]

A word about single lobe cams and valve timing. Because the engine uses only one cam lobe does not mean that valve timing has to be concentric, e.g. 20-70 70-20. It depends on the shape of the valve lifter foot, and the location of the lifter shaft. For example, My Ariel Red Hunter had timing of 18-68 & 63-23. For those few of you who don't know what that means, it is inlet opens before TDC, inlet closes after BDC & exhaust opens before BDC, and exhaust closes after TDC. Just plug the numbers in, and you will know. I've not, so far, found a valve timing diagram for this neat little engine. If someone knows, share it with the rest of us. Timing should be a little bit more radical for the Hawk engine because peak power is at 7500 rpm. My NH (350) Red Hunter peaked at 6250 rpm.
The chassis: The Hawk has a rugged steel frame, with a 3.00 X 21 inch front wheel and tire, and a 4.10 X 18 rear wheel & tire. They have disc brakes front and rear. For whatever that's worth. In my opinion, not much, on a primarily off-road bike. They have quite good, but not the ultimate, front forks. You can improve front fork damping by changing the oil in the forks out to Dexron ATF. If you want even more damping, use Ford type Mercon ATF. On the question of the rear shock, a reservoir type shock is easier to change the damping on. Watch the swing arm bushings carefully, some of them have disintegrated in short order. If it was my bike, when they go, I'd change to urethane bushes. If I was real fussy, I'd change to bronze oilite bushings. Oilite bushings really tighten up the handling. Depends on how fussy you are. AND, all may not be alright at the wheel end of the swing arm. So check to make sure that the axle is a good fit in the wheel adjuster. Some of them have been oversize.
Tire choices. The tire I would run at the rear is a Pirelli MT43, because here we have a lot of rocks and wet small stones in the creeks and water crossings in this part of upstate New York. And what we need is traction, or what English trials riders call "grip". A "security clamp/bolt" is a good idea, because you can run lower tire pressures. And you have to have your carburetion spot on for this kind of riding. What you don't want is wheel-spin. Remember, wheel spin digs a trench, and you have to climb out of that trench, sooner or later. You want to ride steadily through the water, making a nice Vee in the water. If the water is hub deep, you don't want to stop because when that cold water hits the front wheel bearings, the chill will encourage water to get into the bearings. The Vee in the water is to keep the wheel bearings dry. A trials type tire on the front also helps to keep you from slipping on the wet rocks. Stand up when crossing streams in order to lower the outfits center of gravity. If you have to ride very far on the road to get to where the fun is, you might try changing countershaft sprockets for the off-road part of the day. Buy a new chain (Unibear is a good one) and an extra (or two) master links with it. Buy enough chain so that you can get the longer piece for the on road sprocket out of one chain. I would change the bolts that hold the countershaft cover to allen screws, and carry the allen wrench with you. Quality American allen screws, please. I'm sure you will change the sprocket attaching bolts to allen screws as well, so you don't have to carry a ton of tools.

[hertz9753]

I don't know what to say about the picture. I think my Hawk was peeking into the shop when it was young and looking at the old Belsaw grinder and Foley belt sander.

[Ariel Red Hunter]

I mentioned in passing that the Hawk has a 21 inch front rim, and an 18 inch rear. These are probably the closest to perfect sizes around these days for off-road use, and works well on-road as well, with the right tires. You will find you have all kinds of tire choices for those wheels. The tire choices depend on where you ride. Where I live (on the northern slope of the Adirondaks), trials tires (with rim locks) work very well. Wet rocks, tree roots, wet ledge, and they work pretty good on the road. Better than knobbies on the road. Trick with trials tires is low tire pressure, which is why you need rim locks. How low? Depends on your weight. Four to eight pounds front, six to twelve pounds rear is a place to start. I always used to carry a spare front and rear tube with me, just in case. Three tire irons as well. So you probably need to install a burrito tube to carry them in. I always carried a long thin bicycle pump on the frame for emergency uses. You can take some of the plastic trash off the bike to balance the extra weight, if you want. It will pay dividends to spend the money for high quality, heavy duty natural rubber tubes, like Michelins, for example. Natural rubber is tougher and more tear resistant than synthetic rubber is. If you ride a lot on sand, like the Mojave Desert, you may want to switch to a 19 inch front rim for more flotation. But that is an expensive alteration for a entry-level priced motor-cycle. I must warn you that it is imperative to keep all of those spokes snug. I use the short spoke wrench, because it is harder to over tighten them with one. Mark where you start and tighten every third spoke all the way around, then go around again on the next spoke, then again for the last ones. It will take you three trips around the rims to get them all tight. If the spokes are tightend regularly, and you still break spokes, order a set of spokes from Buchannon's and replace them one at a time just like you tightened the spokes, except not as tight until you have got them all in there, then go around three times and get 'm snug. You probably won't have spoke breakage issues if you never let any get loose.

[hertz9753]

I was my shop yesterday and I noticed a KX clutch cable that I bought back in 2000 for my 1980 125. It was still in the plastic and OEM from Kawasaki. It was high up and behind an ED11 tire.

[pete]

[QUOTE=Ariel Red Hunter

Tire choices. The tire I would run at the rear is a Pirelli MT43,

[/QUOTE]

just as a matter of interest the MT43 is a trials tread patten
tire that can be used on the road..

Dunlop 803 or Michlin trials light are to soft and melt with any heat
from the seal... and are all over the place in the corners..

i replaced the dunlop 803s on my trials bike as there were only around
1/4 worn I put them on my XR250... melted the rear tire in 15km on the road..

stay with the pirelli MT43 for road use... or a newish trials patten tire out
is the "MotoZ mountain hybrid" it's diffrents to other trials patten roadable tires
is it has a rounded profile un like the square profile of a normal trials tire...
But if yer want insane traction
& don't ride on the seal use the Dunlop 803 or Michlin trials light..
rubber compond & case constuction are for pure trials use...
even high speed offroad use on hard surfaces can over heat them..

So what I'm saying if yer after a trials patten tire... be careful what yer buy
theres trials patten tires & trials tires.. they a completely diffrent animals these days
not like the old days when a trials tire was a trials tire...

...

[Bruce's]

Holy crap Pete ,on this side of the world we certainly can't hunt or ride on a seal anymore .

[Ariel Red Hunter]

just as a matter of interest the MT43 is a trials tread patten
tire that can be used on the road..

Dunlop 803 or Michlin trials light are to soft and melt with any heat
from the seal... and are all over the place in the corners..

i replaced the dunlop 803s on my trials bike as there were only around
1/4 worn I put them on my XR250... melted the rear tire in 15km on the road..

stay with the pirelli MT43 for road use... or a newish trials patten tire out
is the "MotoZ mountain hybrid" it's diffrents to other trials patten roadable tires
is it has a rounded profile un like the square profile of a normal trials tire...
But if yer want insane traction
& don't ride on the seal use the Dunlop 803 or Michlin trials light..
rubber compond & case constuction are for pure trials use...
even high speed offroad use on hard surfaces can over heat them..

So what I'm saying if yer after a trials patten tire... be careful what yer buy
theres trials patten tires & trials tires.. they a completely diffrent animals these days
not like the old days when a trials tire was a trials tire...

...
Yes as to the short life of modern trials tires, except for the Pirelli MT43. I'm sure the MT43 can not compete mano a mano with the modern super soft trials tires, but works great on dual sports, for my style of riding. Others, particularly in the southwest parts of the United States, may well prefer knobbies. But knobbies don't work that well here, in the northeast. They don't perform all that well at the lower speeds we have to run over wet slippery rocks and tree roots. I've never been able to ride on a seal. They always swim away before I can get close enough to get on one.

[pcspecialist]

Motoz Mountain Hybrid review from a guy that had "run an MT 43 for the last three years without switching to another brand of rear tire."

http://advrider.com/index.php?threads/motoz-mountain-hybrid-review.1043542/

[pete]

I've never been able to ride on a seal. They always swim away before I can get close enough to get on one.





PMSL.......

seal = tar /bitamin.... or what ever you fella's over there call it...

But I think you buggers are just taking the piss....

"taking the piss = having a joke"


..




...

[Bruce's]

I took a piss in your direction Pete .

[Ariel Red Hunter]

PMSL.......

seal = tar /bitamin.... or what ever you fella's over there call it...

But I think you buggers are just taking the piss....

"taking the piss = having a joke"


..




...
tar/bitumin = asphalt/blacktop

[Ariel Red Hunter]

PMSL.......

seal = tar /bitamin.... or what ever you fella's over there call it...

But I think you buggers are just taking the piss....

"taking the piss = having a joke"


..




...Pete, surely you don't think we are cracking your 'nads. Americans aren't that clever, some of my Pommie friends used to tell me.

[Ariel Red Hunter]

For those who ride mostly on-road, and looking for more top end, let's look at some options. A Mikuni VM26, or perhaps a VM28 with the starting enrichment circuit, not the butterfly choke. A quality exhaust system, including the copper o-ring gasket between the head and the head pipe. An one inch to inch and a half intake spacer, to move carburetor furthur from the head. Make this out of plastic to also act as a heat sink. Make sure the inside of this tube is smooth, and exactly the same internal size as the ports on the carburetor and the head. Go to the most open air-cleaner that you can find. Remove the air box completey, or extensively modify it in order to make a "still air" box out of it. Run a 17 tooth front sprocket and go smaller on the rear sprocket. Run the narrowest road tires that will fit the rims. Change the front brake line to one of the stainless steel ones of high quality. Tune carburetor pilot jet, and throttle cut-away for all the low end you can get. This saves the clutch. You know what to do about the main jet.

[Ariel Red Hunter]

While I'm sure that ARH lectures on engine design are pretty boring, I'm going to risk boring you'all just a little longer. I've heard those comments on the superiority of overhead cam engines, especially of Japanese ancestry. But all is not as good as it could be. In fact, there are a surprising number of cam tensioner failures with around ten thousand miles on the bike. Now it may be due to either not enough oil changes, or terrible oil being used. But whatever the reason, cam chains are stretching enough in comparativly low mileage situations to indicate something is wrong. Now, in Classic motorcycle engines, singles especially, only one factory, spread over two brands, successfully used chain driven overhead cams. AJS who came out with the first one, while they were still an independent company in the mid 1920's, and Matchless. During the depression, AJS went down the tubes, only to be bought out by Matchless. Their engineering department at AJS worked the bugs out of their chain drive system. Now we come to the 1960's, when a far eastern tidal wave (Honda) washed almost every other manufacturer away with the tide. With a line of chain driven over head camshaft engines. But with a difference. The chain ran at crankshaft speed, all of the reduction taken at the sprocket in the head, and they buried the drive way inside of the engine on the twins, and as far inside as they could get it on the singles. The AJS and Matchless engines used a gear reduction so that the chain ran at half crankshaft speed, and was mounted outside, on the timing side of the engine. Easy to replace, and much less whip, because it ran so much slower. Because the whip was so much less, AJS used a Weller type chain tensioner. The Japanese, and clones used a pushrod type tensioner, probably because there was too much chain whip for a Weller type tensioner. And these automatic pushrod tensioners are breaking, dropping little metal bits into the works. Think about that before you decide that a pushrod engine with gear driven cam is so hopelessly out dated as to be safely ignored.

[Ariel Red Hunter]

Un fortunatley, cam chains suffer from more than just whip. It's called fling. Fling is even harder on a chain than whip is. With whip, at least some oil gets in to lubricate the links. With fling, not so. When a chain is running between two sprockets, there is a chain speed (in feet per minute) where the chain is tight all the way around, and no oil gets to the loaded side. This overheats the roller axle ~ disaster comes, sooner or later. Running a chain at high crankshaft speeds can cause fling. By reducing chain speed with a reduction gear, the chain never turns fast enough for fling to happen. It has by now surely occured to you guys why modern OHC engines don't use reduction gears for cam chains. It costs more. The only way you can get close to the cost of a pushrod engine with a gear driven cam, is to eliminate the gear reduction of the timing chain. Even relatively low rpm OHC engines have chain problems. This surprised me, but 650 Suzuki Savage are even having this problem.

[Ariel Red Hunter]

Those of you who have been following this thread may have noticed that I haven't said a word about ignition or AC vs. DC alternators. That is because when you get very far past a magneto, or a generator and points/condenser ignition system, well, I'm over my head. But when it comes to thermodynamics, hydraulics, and mundane things like why you want the crankcase to run at a partial vacuum, and even wheel and tire sizes, then I know something. I even understand motorcycle frame geometry. I can even tell you why something ought to be there when it isn't there. I was even a production engineer at International Harvester for a while. If I worked for Bashan, the first two things I would change are the location and/or type of rear wheel master cylinder, and the swing arm bushings. I hope the reasons for this are obvious. Next would be the rear chain quality issue. Note that two of these problems are vendor problems. When you are producing as many motor cycles per month as Bashan is making, you can swing a pretty big stick. Bashan should be telling those two vendors that if you can not find a way to improve the life of these two parts, Bashan will have to look elsewhere for swing arm bushings and drive chains. And at the same or lower price. If you think this can't be done, you are wrong - Ford Motor Company does it all the time. To illustrate that point, when Ford bought Jaguar, one of the first things they did was to see where the warranty claims were. Electrical problems. Since Jaguar started in the 1930's, they had been using Joseph Lucas electrical parts. Now to the younger set, in the old days, Joe Lucas was known as "The Prince of Darkness". Need I say more? So Ford told Lucas if they couldn't get the quality up to current standards, they were going to switch to Bosch, or Motorcraft, or Autolite, or even Delco-Remy. Lucas got the quality up.

[Ariel Red Hunter]

I ran across an old interview with Joe Craig today, and I thought I would share a few snippets of it with you. Joe Craig was the guru of the Norton racing department from 1930 until they quit making Manx Nortons. He brought the single cylinder motorcycle to as close to perfection as anyone ever has. I'm going to put him in quotes. When a quote ends, and another one starts, then a new quote. "High performance is achieved chiefly by admitting the greatest weight of charge (at high piston speeds) and burning it efficiently. The highest possible weight of charge is obtained through having a long induction period and by making maximum use of the kinetic energy of the exhaust gasses from the previous stroke. The pressure difference across the exhaust valve encourages the new charge to flow readily into the cylinder. Engine torque is of prime importance, and although an increase in bhp may be possible between, say, 6000 and 7000 rpm (he is talking about the 30M engine, which had a stroke of 100 mm, very close to 4 inches)the torque at this speed may be decreasing. Briefly, we aim for the highest torque at the highest possible engine speed while ensuring that the torque at lower r.p.m. does not suffer unduly in consequence." Now think that statement through. If you have looked at very many torque curve of gasoline engines, you will notice that torque makes a gradual climb to peak, and thereafter falls off rapidly. HP is generally assumed to be torque, in foot-pounds, times rpm, and then this total divided by 5250. Everyone (even me) has one of those pocket calculators that make charting this stuff easy. So take the Hawk's torque figure at 5500, and elevate it to 6500 run it through the calculator and see what happens. And here endeth the lesson for today.

[Ariel Red Hunter]

Those of you who have struggled through reading my posts, may have noted that I talk about eastern riding and western riding as if they are two different worlds, well, they pretty well are. Except for the Pacific North-west, which has similarities to the east. Eastern woods terrain may well be better traversed with trials type tires,because of traction over wet rocks, stream beds and coming out of a stream bed with tree roots to get over, and logs to get over in the woods. Out west, where I grew up, cow trailin' and desert riding was what we did. And fire roads. Knobbies work well for that type of riding. So to forks. You will find it easier to ride in the east with lightly damped front forks. One of the primary techniques for getting over logs is to approach it slowly, put your weight on the handle bars to compress the forks, then pull back on the bars and give it a shot of throttle so the bike rears up to get the front wheel on the top of the log, then feather the throttle, and using momentum to get the rear over. Too much throttle and the rear wheel will spin and leave you "high centered". You will eventually learn to lean forward again a little bit in order to get all of the rear suspension extension possible. It's sort of a motorcycle ballet. You will have to practice this. It will take more than 10 minutes to learn this skill. Lightly damped forks work well for this. Lightly damped realistically means thinner fork oil. For pavement riding, heavier fork oil is indicated, also for western riding.

[Ariel Red Hunter]

The "Wizard of Bracebridge Street", that was Joe Craig. Joe was a great engine man, but not really a chassis man. From the end of the TT races on, he was scheming and working to win the next one. Joe was interested in two things - useable engine power, and reliability. Bracebridge Street, in Birmingham, was the home of Norton Motors for about fifty years. So, to go on with Joe's interview - - "When the best compromise of inlet and exhaust port shape has been established in cojunction with the length of valve opening period, diameter of the valve head, and the (mechanical) displacement of the valves dictated by the shape of the cams and the required "overlap," work begins on improving the combustion of the charge. The aim is to provide the optimum amount of "swirl" -- agitation of the mixture-- and so improve the evenness of the burning. Swirl is influenced by port shape, diameter and angle, valve diameters, and the configurations (shape) under the valve head. Governed in this way by compromise, the best set of conditions is established. The combustion-chamber shape then receives attention so that the fuel is burned as efficiently as possible. It is of the utmost importance that the surface-are to volume ratio is as low as possible, for it is this ratio which decides the proportion of heat that will be retained in the charge and the amount that will be dissipated through the head, barrel, and valves. Heat retained is capable of doing useful work, but heat dissipated is responsible for many of the troubles with the internal combustion engine". Now, ladies and gentlemen, I think that is enough to chew on, and digest for one day.

[pistolclass]

ouch you hurt my cerebrum.

[Ariel Red Hunter]

ouch you hurt my cerebrum. Sorry, such was not my intent. I put this up here as a guide for those who are searching for more power than a simple carburetor and exhaust change can supply. Food for thought, in other words.

[Ariel Red Hunter]

For me anyway, the best way to get something out of technical topics like this is to read them over, at least three times, over three days. Then the salient points sort of percolate through your brain, to be re-called on demand. So let's read on. "No advantage is to be gained by allowing a Manx engine to turn over at speeds in excess of 6200 rpm for the 500cc, and 7200 for the 350cc. Engines will usually withstand a sudden increase of, say, 500 rpm momentarily, as for instance a gear is missed, or a chain breaks; but when an engine is over revved the big end (rod) bearing, gudgeon pin (wrist pin) and piston bosses are subjected to excessive overloading. It is difficult to take any steps to prevent this occurring, apart from impressing upon the rider how harmful and expensive the practice of over revving can be." - - "While there is at present there is a tendency towards "squarer" (shorter stroke) engines, we feel that our 71X88mm (350) and 79.62X100mm (500) power units have been - and are - quite successful in the hands of the general racing public. Although we agree that the squarer (shorter stroke) engine may have the ability to rev more for similar piston speed and inertia loading, one should not overlook that higher engine speed is of no merit unless accompanied by a substantial gain in power." - - "The material for the inlet (valve) guide is phosphor bronze and for the exhaust, chromium bronze. The high thermal conductivity of chromium bronze enables full use to be made of sodium cooled type exhaust valves. In other words, the hot stem of the exhaust valve is able to lose its heat rapidly through such a guide, thereby lowering the temperature of the exhaust-valve head." - - "In an exhaust system for a racing engine, the gases must be dis-charged so that the piston works against the minimum possible gas pressure. The kinetic energy of the (exhaust) gas must be utilized in such a manner as to produce the maximum negative pressure in the cylinder towards and at the end of the exhaust stroke. Use can then be made of a large valve overlap to get the inlet gas moving in readiness for the next filling stroke. It has been established that the combination of exhaust pipe length and diameter is important in achieving the best possible results, and that no one combination is equally efficient over the whole speed range of the engine. Usually a long pipe of small diameter is good for power at low rpm, while a shorter pipe of larger diameter is better for power at high rpm. It is necessary to compromise with a pipe diameter and length wich gives the best results at the most used part of the engine-speed range. The length is often less than the regulation requirements for (road) racing, and in the early days the megaphone was introduced to bring the length of the exhaust pipe to that required by the regulations. In later years, however, the exhaust pipe has been subjected to intensive investigation, and the angle of the taper of megaphone have been found to be important in achieving the greatest possible extractor effect, and the consequent benificial influence on top-end performance."

[Ariel Red Hunter]

For those of you who have been reading this column, thread or whatever it is, let us discuss what we may have gleaned from 'ole Joe's rantings. What he has to say about surface-to-volume ratios is beyond our control with the Hawk's engine. The port size is pretty well fixed, and from what I've seen of it in various pictures posted on C/R, the shape is pretty good. So is the finish. The problems start on either side of the head. The standard carburetor is very difficult to find jets for, as I learned to my sorrow in the 1960's when I was wrenching a 125 Honda twin road racer. I had read, in Phil Irving's book "Tuning for Speed", why moving the carburetor away from the head's inlet port helped cylinder filling, and increased torque. I tried it and it made a big difference. We made, on a lathe, a three inch inlet manifold as an experiment, out of a piece of magnesium alloy that was laying around the shop. We even turned cooling fins on it. The cooler the mixture, the more it weighs - hence better cylinder filling = more torque = more power. It worked fine. I weighed about 225 in those days, and it would accelerate in fifth gear up hill carrying me. Pretty impressive, it actually surprised me. If you are riding mostly on the road, you probably need all the torque and horsepower you can get, so the exhaust system is the next problem. I have seen photographs of the inside of the Hawk (and brothers under the skin) head pipe. You don't want any restrictions in the exhaust that don't serve a purpose, like muffling. In the pictures I've seen, sloppy welding, and a furry gasket between the head and head pipe is bad news. Never mind having a tiny catalytic converter stuffed in there. The head pipe is really stifling horsepower. Next comes the muffler. I don't know how restrictive it is, all I know about it is I would change it too, partly because I want an exhaust just loud enough that I can hear it with a helmet on. I would even consider making a Brooklands Silencer for it. I think the pipe diameters are spot on for this engine, and the uses we have for it. So, you need a new head pipe and one of those Honda copper o-ring gaskets for it. A Brooklands Silencer will add about 1 horsepower over an open pipe, for your information.

[BlackBike]

I tell you red, you need to get one of these cheapie bikes to tinker with and get you a young test pilot for trials.:)

[Ariel Red Hunter]

I tell you red, you need to get one of these cheapie bikes to tinker with and get you a young test pilot for trials.:)Good idea! Also good to know that everyone reading my deathless prose knows what a Brooklands Silencer is, so I don't have to try to describe it.

[hertz9753]

Isn't that something that an English hitman uses to keep his gun quiet?

[Ariel Red Hunter]

Isn't that something that an English hitman uses to keep his gun quiet?Funny, but not quite. Brooklands was a pre-war racing venue that required mufflers (silencers to the British).

[hertz9753]

http://www.austin7club.org/How%20To%2011.htm

It's also a race track in the UK built nine years before my dad was born and you can still buy the silencers from many websites in the UK.

http://www.classicmotorcyclespares.com/index.php/default/exhausts/silencers/other-classic-bike-silencers/silencer-brooklands-can.html#Silencers

Most people don't know how much good info is in your posts but just like you I am a knowledge sponge.

[pete]

Most people don't know how much good info is in your posts but just like you I am a knowledge sponge.



yer a bit of stuff yer tend to forget about over the years...




...

[Ariel Red Hunter]

http://www.austin7club.org/How%20To%2011.htm

It's also a race track in the UK built nine years before my dad was born and you can still buy the silencers from many websites in the UK.

http://www.classicmotorcyclespares.com/index.php/default/exhausts/silencers/other-classic-bike-silencers/silencer-brooklands-can.html#Silencers

Most people don't know how much good info is in your posts but just like you I am a knowledge sponge.A racing venue is just fancy-pants verbiage for a race track. What they found out, eventually, on the Prony Brake (a mechanical dynomometer) was that a well selected Brooklands Silencer actually increased horse power by 3 or 4 percent over a straight pipe.

[Ariel Red Hunter]

A Prony Brake is a method of reading the torque of a rotating shaft. It has been around for at least 150 years. You will immedietly grasp the fact that a crankshaft on a internal combustion engine is a rotating shaft. If you could mount a drum brake on the crankshaft, have a freely rotating brake backing plate, connect a bar exactly one foot long to said backing plate, arrange an accurate scale for the one foot long lever (one foot from the crank center line), you would have a Prony Brake. And have an answer in foot ponds. Warm the engine up, and start reading the numbers off of the scale at, say, 250 rpm intervals. Obviously, as the rpm's climbed, you had to tighten the brake bands or shoes in order to hold the rpms steady at that rpm. Yes, you had to cool the brakes. Brake bands were used for a long time, because you could cool them by dripping water on the band and drum. If you want to build one of these brakes in your garage, you can do what I did, and use a Farmall "M" brake from either the left or right side to build the brake part. And yes, I had a beer keg of water that dripped down to keep it from over heating. The "M" has external brake bands, that's why I used that brake. And now you know where the phrase "Brake Horsepower" comes from. B.H.P. If you decide to build your own Prony Brake, let me know - I know where to find the parts.

[Ariel Red Hunter]

OK, you've already decided (I think) how far you want to go with the engine. So let's see where we can reduce the losses. Perhaps the first thing is the drive chain run. First problem is the counter-shaft sprocket. The wiggle is not good, so we are going to eventually shim it one way or another to get rid of the wiggle, and have it absolutely dead nuts centered on the rear wheel sprocket. To do this we have to drop the chain and run a straight edge from the rear sprocket to the front sprocket. If they are more than a quarter inch out of true, the first place to look is at the rear wheel alignment with the front wheel, and making sure that the front tire is centered in the rear tire. I use two bed frame irons and run them from the back wheel to past the front. That will tell you if the rear tire is out of line with the front ("dog tracking"). Correct that problem first. If all is right, and I mean RIGHT!, then check the sprocket run. It is possible you will have to shim either to get that dead on. I think this is the perfect time to replace the counter shaft mounting bolts, and the countershaft sprocket cover with high quality allen screws. In Metric sizes, of course. So now you have reduced chain losses to the minimum, right? Next is the chain. I prefer a high quality non o-ring chain. What? Why? Because of less drag, or frictional loss. When you are playing with around fifteen horsepower, and want speed, you have to cut every loss you can. Cutting losses is usually much cheaper than adding horsepower. If we can save only one and one-half horsepower, that is 10%! Next is wheels and tires. Scrub losses from wide tires eat horsepower. If your buddie does everything you do, and stays with 3.00X21 front and 4.20X18 rear, but if you run a 2.75X21 speedmaster front, and change to a 21 inch rear rim and mount a 3.00X21 on the rear, you will out run him on top end every time. And maybe corner faster as well. Don't believe me? Look at bicycles. Notice that the faster one run large diameter but skinny tires. They don't build them that way for looks.

[Ariel Red Hunter]

Hopefully, Those legions of my readers who suffered different levels of heart failure yesterday over my comments about why you want to run a 21 inch rear wheel, if you are looking for all the speed you can get, have recovered. Indigestion is, I hope, also under control. Somewhere in the dim, distant past, I read that a human being can produce between 1/4 and 3/8 of a horsepower for any longer than a few moments. So therefore, a bicycle has to be designed to get the utmost out of the available horsepower. A motorcycle could be described as a sophisticated motorized bicycle. Now the Hawk is designed as a dual purpose motorcycle, obviously. But, if we choose to spend 90% on pavement, and only ride dirt/gravel roads and hard packed trails 10% of the time, and want all the speed we can get, a 21 inch rear is one of the steps to getting the highest possible maximum speed out of this particular scoot. My Ariel Red Hunter came from the factory with a 2.75X21 inch front tire and wheel, and a 3.00X20 rear tire and wheel. But good luck finding 3.00X20 tires and rims today. My Ariel came with an Avon Speedmaster front tire (ribbed), and an Avon speedmaster rear, which was not ribbed, but wiggly-grooved. And moderatly high tire pressures. About 25 front, and 32 rear, if memory serves. And it takes a different, older riding style to get the best out of it. You don't throw the bike in the corners, you squeeze it, keeping your knees in. Smooth riding. If you are up to a little youtube-ing, I suggest you watch Mike Hailwood's technique in the race at Mallory Park in 1978, riding a Ducati V-twin against all the super horsepower 4 bangers. Watch how smoothly he rides. This is a fifteen minute education on how to ride a skinny tired, comparatively low horsepower machine.

[BlackBike]

I was worried, thinking you were going for a pair of crank arms and petals for that extra 3/8 hp boost:lmao:

[Ariel Red Hunter]

I was worried, thinking you were going for a pair of crank arms and petals for that extra 3/8 hp boost:lmao:Just LUV a guy with a sense of humor! Really I do. But, this proves that at least one guy read it.

[Ariel Red Hunter]

If you choose to re-make the Hawk into a corner scratcher, like I have been talking about, something is going to have to be done about the swing arm bushings. When you put your Geoff Duke face on, you won't like that hinged-in-the-middle feeling. Urethane bushings are better than what's in there - and bronze bushings will really tighten things up. Front fork oil up-graded to at least Dexron ATF. If you want it a little firmer, try Mercon ATF. I would try to find Ferodo lined pads for the brakes. Remember, if you put Ferodo pads on, you have to warm them up before you get real serious. This is why 175's, 200's and 250's are so much fun. You really get to run the little bastards as hard as you can without getting into serious trouble. Maybe that's why I loved my little Model 14 AJS so much. Just ride the heck out of it, and enjoy. The Model 14 wasn't perfect - it came with 17 inch wheels. Even so, it would get right on down the road. Somewhat the same engine as a Hawk but tuned pretty good right from the factory. My uncle raced a 350 "Cammy" AJS on the board tracks in the 1920's. It was fast, but fragile. His nickname for it was "the valve swallower". The world has made tremendous strides in metalurgy and lubricants since those days. Back to the Hawk-a-thon. Be sure to change the brake fluid to DOT 3 or better. If you want to spend the time and money, you could do some work on the camshaft, to get more overlap. Pull the head to make sure the valve seats are good. If you are going to be running a lot at continious high rpm, look after the valve springs. If you can find high octane fuel without ethenol in it, run that. Pay attention to spoke tension. And have fun.

[Ariel Red Hunter]

I thought I covered reducing friction pretty well, but I just remembered that when I visited Andy Kolbe's BSA/Honda shop in Woodland Hills, Calif., they were working on their Gold Star flat tracker. I think they were getting it ready for the Sacramento Mile. Sacto, we called it. Anyway they were testing various ways to grease the wheel bearings. They spent all afternoon and evening trying different bearing greases. They would grease it up, mount it on the bike, and have the same guy spin the wheel, and time it with a stopwatch until the wheel stopped. Vaseline was the winner. They replaced the modern spring type rubber seals with leather seals that they punched out on the spot. "I can't believe that made any difference" I said. "Oh yeah, the leather seals barely touch the axle, and the tire revolved about 2 minutes longer." That is what is known as taking pains.

[fredweb]

I thought I covered reducing friction pretty well, but I just remembered that when I visited Andy Kolbe's BSA/Honda shop in Woodland Hills, Calif., they were working on their Gold Star flat tracker. I think they were getting it ready for the Sacramento Mile. Sacto, we called it. Anyway they were testing various ways to grease the wheel bearings. They spent all afternoon and evening trying different bearing greases. They would grease it up, mount it on the bike, and have the same guy spin the wheel, and time it with a stopwatch until the wheel stopped. Vaseline was the winner. They replaced the modern spring type rubber seals with leather seals that they punched out on the spot. "I can't believe that made any difference" I said. "Oh yeah, the leather seals barely touch the axle, and the tire revolved about 2 minutes longer." That is what is known as taking pains.

Vaseline has a melting point of 99deg F. I wouldn't expect that to last long in a bearing. It will run out the bearing and probably catch fire after the bearing heats up. The grease being used isn't as important as how its used. If you want to reduce friction use lithium based grease and just barely coat the balls and race. I used to grease the bearings and then use compressed air to blow out the excess. This reduces friction and in turn reduces the heat generated. Vaseline is not a very good idea at all.

[Ariel Red Hunter]

Vaseline has a melting point of 99deg F. I wouldn't expect that to last long in a bearing. It will run out the bearing and probably catch fire after the bearing heats up. The grease being used isn't as important as how its used. If you want to reduce friction use lithium based grease and just barely coat the balls and race. I used to grease the bearings and then use compressed air to blow out the excess. This reduces friction and in turn reduces the heat generated. Vaseline is not a very good idea at all.I didn't know lithium grease was available in 1960. They may have used the Vaseline for a benchmark. I've used Vaseline grease for this and that for years and never had melting at low temperature problems. I've used it on cows before for barb wire cuts, and their body heat is 104, I think. Anyway that's the number that sticks in my mind. I doubt the flash point for vaseline is anywhere near 99f.

[fredweb]

I didn't know lithium grease was available in 1960. They may have used the Vaseline for a benchmark. I've used Vaseline grease for this and that for years and never had melting at low temperature problems. I've used it on cows before for barb wire cuts, and their body heat is 104, I think. Anyway that's the number that sticks in my mind. I doubt the flash point for vaseline is anywhere near 99f.

The flash point for vaseline is around 200deg F. certainly low enough to be ignited by friction from a poorly lubed bearing. putting vaseline on a cow is a lot different than using it for a bearing grease. My point was that the grease used is less important than application and use provided that the grease actually stays on the bearing surfaces and prevents friction heat. anyone that uses vaseline for bearing grease is asking for trouble. I've only been a mechanical engineer for 25 years but what the hell do i know. go ahead and use vaseline. They will sell you all the bearings you want i suppose.

[Ariel Red Hunter]

The flash point for vaseline is around 200deg F. certainly low enough to be ignited by friction from a poorly lubed bearing. putting vaseline on a cow is a lot different than using it for a bearing grease. My point was that the grease used is less important than application and use provided that the grease actually stays on the bearing surfaces and prevents friction heat. anyone that uses vaseline for bearing grease is asking for trouble. I've only been a mechanical engineer for 25 years but what the hell do i know. go ahead and use vaseline. They will sell you all the bearings you want i suppose.Hmmm. The flash point I found for Vaseline is stated at 182 degrees Centigrade to 221 degrees Centigrade.

[fredweb]

Hmmm. The flash point I found for Vaseline is stated at 182 degrees Centigrade to 221 degrees Centigrade.

You are correct. I F'd when i shouda C'd thats still around 400 F and thats still within practical range for a metal on metal friction. First theres smoke. THen theres fire. but way way way before that you have damaged bearings and maybe even a broken neck.

[Ariel Red Hunter]

You are correct. I F'd when i shouda C'd thats still around 400 F and thats still within practical range for a metal on metal friction. First theres smoke. THen theres fire. but way way way before that you have damaged bearings and maybe even a broken neck. I sure don't reccomend anyone riding a Hawk, or any other consumer use motorcycle using Valveline for wheel bearing grease, But we did use the stuff on the wheel bearings of a BSA Gold Star flat tracker. And I never saw smoke or blued bearings or any other problems with that bike. Flat track racing is usually over short distances. Usually less than 50 miles at average speeds of around 100 mph. You go through 5 mile heats, If you finish in the top 3, you automatically transferred to the main event, which was usually a 20 lap, 10 mile final. The problem was not usually too thin a grease, it was a problem of not running long enough to heat the grease to a semi-liquid state. That's why we used Vaseline.

[fredweb]

So i have been reading the thread and you all are going about this all wrong. I have a hawk that will push 75 indicated with stock gearing. This is because i have the carb, valves, and spark balanced for the highest rpm possible. To do this you cant rely on jet kits. You have to start with a small jet and drill it out(by hand) a little at a time until you get the proper mix within the capability of the mixture screw to compensate. This will also result in a much smoother running engine even at high rpm. If you get your mixture right you should see a header temp of about 600-800 F Ideal is about 750 F. too hot and your lean. Too cold and your rich. Now that this is after setting the correct valve clearance and this might take a few tries because the tolerances the chinese are used to aren't awesome.

Once you get this done correctly you can start thinking about gearing. Doing and gear change before this will be counterproductive as you wont have maximum power to work with. This too may be trial and error as it can depend greatly on your riding style. If you gear it so high that it barely runs in 5th you will generate unnecessary heat and can do engine damage. Not to mention burn out the clutch. I would recommend working up to a point where you can drive ok in fifth and still slow 20mph and pick it back up in 5-7 seconds. Any higher and you risk engine damage. the chain will create some resistance but really the difference between o-ring and not is probably moot. If you are seeing a noticable difference here at all its probably because you have too tall gearing anyway so back it off. and make sure your chain is adjusted properly, use the appropriate oil viscosity for your area/air temp.

Thats about all you can do without moding the engine. Increasing the compression ration will pay off more than anything but you cant just deck the head or you will bend valves and all sorts of other nasty stuff. A good aftermarket wont help on these bikes as they have too low hp already and the factory pipe is basically free flow already. Changing the air filter to a better/ less restrictive may help get air through the motor but do this before valve and jetting or you will have to start over.

That's pretty much it short of adding fuel injection and / or a turbocharger. This is almost a fools errand because it will cost you a grand and at that point you could sell the hawk and take the grans and probably buy a used xl650 or something similar that would do 90+, but if you are interested there are options for this out there. Its certainly not for the novice though as you would need to splice in the electronics that control both of these. Porting and polishing your intake and exhaust ports is a waste of time. Nobody, and i mean nobody polishes a port anymore. you can open them up if they are not a match with the carb flange but leave them a bit rough as this will help the fuel mix with the air. You need a little turbulence for this to happen super smooth port walls dont facilitate this.

And for anyone who is curious i used to work for a company that builds drag racing motors so i have a little experience with getting the most out of an engine/vehicle.

[Ariel Red Hunter]

Yes, even I am a little tired of Joe Craig. But very rarely do we get to pick the brain of a man who had so much to do with the racing success of the single cylinder, air-cooled motor cycle. So, onwards and upwards: "In a naturally aspirated engine, the incoming air has imparted to it a velocity sufficiently high at the carburettor jet to raise petrol and to continue at an increasing velocity along the port until it enters the cylinder. The force mainly responsible for this velocity is the negative pressure created by the descending piston. This negative pressure occurs only for 180 degrees of crankshaft movement and at, say, 6000 rpm, precious little time is afforded to this cylinder filling period. However, because the gas column is travelling at such a high velocity, cylinder charging continues until the pressure created in the cylinder by the rising piston is equal to the pressure exerted by the gas column. In the case of the Manx engines, this pressure balance takes place some 67 1/2 degrees after bottom dead center. This ramming effect occurs as a result of high engine rpm, the shape of the valve-lift curve and the length, diameter and shape of the inlet tract. As I have mentioned, the kinetic energy of the exhaust gases helps the inlet charge provided, in the case of the Manx engine, the inlet valve is open some 60 degrees before top dead centre." It might take a little effort and time to digest all of that.

[fredweb]

Yes, even I am a little tired of Joe Craig. But very rarely do we get to pick the brain of a man who had so much to do with the racing success of the single cylinder, air-cooled motor cycle. So, onwards and upwards: "In a naturally aspirated engine, the incoming air has imparted to it a velocity sufficiently high at the carburettor jet to raise petrol and to continue at an increasing velocity along the port until it enters the cylinder. The force mainly responsible for this velocity is the negative pressure created by the descending piston. This negative pressure occurs only for 180 degrees of crankshaft movement and at, say, 6000 rpm, precious little time is afforded to this cylinder filling period. However, because the gas column is travelling at such a high velocity, cylinder charging continues until the pressure created in the cylinder by the rising piston is equal to the pressure exerted by the gas column. In the case of the Manx engines, this pressure balance takes place some 67 1/2 degrees after bottom dead center. This ramming effect occurs as a result of high engine rpm, the shape of the valve-lift curve and the length, diameter and shape of the inlet tract. As I have mentioned, the kinetic energy of the exhaust gases helps the inlet charge provided, in the case of the Manx engine, the inlet valve is open some 60 degrees before top dead centre." It might take a little effort and time to digest all of that.

While this is all relatively accurate, it has f*#k all to do with actually setting up a bike for maximum power/torque curves to achieve optimal performance. Every forum i have ever been on has had some know-it-all jackwagon like you that is always threatened by anyone else having an opinion. The main difference between you and I is that I don't really care if anyone reads the post I wrote or follows any of the instructions. To be honest those recommendations are only jumping off points as it all takes a bit of experimentation to get things just right. I was trying to be helpful. The post you provided was meant solely to confuse and baffle. I don't know if your just that insecure that you have to constantly be the center of attention here but i'll let you have it. You can fumble f*#k around til the end of time for all i care. Good luck with that.

[Republic]

So i have been reading the thread and you all are going about this all wrong. I have a hawk that will push 75 indicated with stock gearing.

What rpm's are you running at at 75 with stock gearing?

[Ariel Red Hunter]

While this is all relatively accurate, it has f*#k all to do with actually setting up a bike for maximum power/torque curves to achieve optimal performance. Every forum i have ever been on has had some know-it-all jackwagon like you that is always threatened by anyone else having an opinion. The main difference between you and I is that I don't really care if anyone reads the post I wrote or follows any of the instructions. To be honest those recommendations are only jumping off points as it all takes a bit of experimentation to get things just right. I was trying to be helpful. The post you provided was meant solely to confuse and baffle. I don't know if your just that insecure that you have to constantly be the center of attention here but i'll let you have it. You can fumble f*#k around til the end of time for all i care. Good luck with that.Well, thank you ever so much for your kind comments.

[Bruce's]

Story time is getting a little out of hand .

[pete]

I sure don't reccomend anyone riding a Hawk, or any other consumer use motorcycle using Valveline for wheel bearing grease, But we did use the stuff on the wheel bearings of a BSA Gold Star flat tracker. And I never saw smoke or blued bearings or any other problems with that bike. Flat track racing is usually over short distances. Usually less than 50 miles at average speeds of around 100 mph. You go through 5 mile heats, If you finish in the top 3, you automatically transferred to the main event, which was usually a 20 lap, 10 mile final. The problem was not usually too thin a grease, it was a problem of not running long enough to heat the grease to a semi-liquid state. That's why we used Vaseline.

Pretty sure Ivan never used vaseline as a wheel bearing grease...
He only done 4 laps per race...

I think any gain would be more in the head than on the track...



...

[fredweb]

What rpm's are you running at at 75 with stock gearing?

I'm not sure as i don't have a tach. I can assure you its wound out tighter than frog pussy though. Its got to be the absolute limit for that engine. at this point gearing is the only way up, but i have enough power and torque to go up. I bet if i get it right i can bury the stock speedo.

[Ariel Red Hunter]

Pretty sure Ivan never used vaseline as a wheel bearing grease...
He only done 4 laps per race...

I think any gain would be more in the head than on the track...



...Pete, there were more or less 21 Gold Stars, all dynoed on the same dyno (C. R. Axtell's) and all of them hunting first place money. You will be amused, perhaps, to know that one of our real hot shoe riders, "Slidin'" Al Gunter, threw a tarp over his bike when he worked on it in the pits. "Why the tarp, Al", I once asked him "The baby needs new shoes, and none of you S.O'B.'s are going to get any free speed secrets off of me." Desperate men do desperate deeds.

[pete]

ARH you need to put a few warrings in your posts....
not everyone is as all knowing as you.... there could be people that know no better and could try vaseline in there wheel bearings...

This is a CB form not a flat track one... your thread here is headed "HAWK TALK"

DO NOT put Vaseline in your wheel bearing...
it will resalt in the wheel bearings seizeing.. you doing a face plant...

bearings require a proper lubcant to work... They need friction
to make the balls or rollers roll with out friction they skid in the races
the heat from that could seize the bearing.. And the bearings
will be toast in a very short time..

VASELINE IS NOT A SUITABLE LUBCANT FOR BEARING...




...

[Ariel Red Hunter]

ARH you need to put a few warrings in your posts....
not everyone is as all knowing as you.... there could be people that know no better and could try vaseline in there wheel bearings...

This is a CB form not a flat track one... your thread here is headed "HAWK TALK"

DO NOT put Vaseline in your wheel bearing...
it will resalt in the wheel bearings seizeing.. you doing a face plant...

bearings require a proper lubcant to work... They need friction
to make the balls or rollers roll with out friction they skid in the races
the heat from that could seize the bearing.. And the bearings
will be toast in a very short time..

VASELINE IS NOT A SUITABLE LUBCANT FOR BEARING...




...Pete, I've already warned people not to use Vaseline in their wheel bearings. I don't think anyone on here wants to go through what we went through after every race meeting. Every week we changed the engine oil (I used AeroShell 70-50), cleaned and flushed the wheel bearings, re-cut the tires, re-set valve clearances, tire pressure, and attended to any other things that need doing. Unless we had two race meeting in a week. Then we did it all twice.

[Ariel Red Hunter]

O.K., We have played (at least in our minds) with speed tuning the Hawk engine. So let's get back to reality for a moment or two. As an on/off road bike, what we need is as much low and mid range power as we can get without mortgaging 40 acres of prime Mississippi Delta bottom land to do it. If your swing arm bushings are still primo, just grease the swing arm hinge axle, just snug up the nut enough to take up the slack, left to right, and double nut it so it stays that way. That should last quite a while. Decide what kind of tires will be best for where you ride, trials type or knobbies. With trials type tires you will have to ride more standing up, not just to get the center of gravity lower, but because trials tires are more square to the road in order to get more traction or grip. You might as well get Michelin, or other, heavy duty tubes and install a security bolt at least on the rear. Then you can run low tire pressures without worrying about the valve stem getting eaten alive. Pete suggested running co2 instead of air in the tires because with co2 the tire pressure goes down when going slowly off road, but on road the build up of heat in the tire raises tire pressures. Another benefit of low tire pressures, which let the tire have a bigger footprint, is it lets the tire throw mud better. And, at least in the Eastern United States, You will be happier if you have fine tuned your carburetor to have instant response right from idle to wide open. I'd also set the idle speed as low as it can go, and still pull the bike on level ground without having to gas it up. No, not from a dead stop, but engine idleing in first gear after you've gotten it moving. If it wants to go too fast in low gear when on downhills, shift up to second gear and turn off the ignition with those ever so handy little red buttons on the right (starboard) handle bar. As you roll out on the bottom, turn the ignition back on, and select the gear you feel comfortable with. The less brake you use, the less often you get to test your helmet. I think that spending more time standing in the rough stuff will make the rear suspension work better, to the point where you don't need to change the shock. I, personally want an exhaust system just loud enough to be able to hear it with a helmet on. Much more useful than a tachometer off road. Your ears will very quickly learn to tell you when the rpm is too low, or too high.

[BlackBike]

If it wants to go too fast in low gear when on downhills, shift up to second gear and turn off the ignition with those ever so handy little red buttons on the right (starboard) handle bar.

so that's what that dam things for? i thought it was there to run your battery down while cranking the electric starter :lmao:

[Ariel Red Hunter]

If it wants to go too fast in low gear when on downhills, shift up to second gear and turn off the ignition with those ever so handy little red buttons on the right (starboard) handle bar.

so that's what that dam things for? i thought it was there to run your battery down while cranking the electric starter :lmao:Ha-Ha, but no that is not what they are there for. They are there because a bunch of politicians decided we absolutley had to have them in order to ride the d++++d things without getting hurt.

[pete]

I dont use the motor going down hills "real hills"
clutch in or pick nutrual...
The motor has no idea what the rear wheel is doing..
I do..

but it;s a diffrent ball game with the rekluse auto/manual clutch..
dab the rear brake and it drops out /disingages free wheels..
blip the throttle and it reingages..




,

[Ariel Red Hunter]

I dont use the motor going down hills "real hills"
clutch in or pick nutrual...
The motor has no idea what the rear wheel is doing..
I do..

but it;s a diffrent ball game with the rekluse auto/manual clutch..
dab the rear brake and it drops out /disingages free wheels..
blip the throttle and it reingages..




,Rekluse auto manual clutch? Sounds like the real deal. I like to have some engine drag going down "real" hills. Just my opinion, and comfort zone, I guess. On older bikes, I used the compression release to do the same thing. The compression release had the advantage over switching off of being variable in action.

[pete]

Rekluse auto manual clutch? Sounds like the real deal. I like to have some engine drag going down "real" hills. Just my opinion, and comfort zone, I guess. On older bikes, I used the compression release to do the same thing. The compression release had the advantage over switching off of being variable in action.


the two sections of the unit have wedge shaped weights between them..
the unit exspands as the revs come up compressing the clutch plates but
you can still pull the clutch lever opening the clutch pack more than what the rekluse
unit can exspand giving a full manual clutch still...

http://i1244.photobucket.com/albums/gg563/petenz1/SAM_0003-1.jpg (http://s1244.photobucket.com/user/petenz1/media/SAM_0003-1.jpg.html)

http://i1244.photobucket.com/albums/gg563/petenz1/SAM_0007.jpg (http://s1244.photobucket.com/user/petenz1/media/SAM_0007.jpg.html)

[Ariel Red Hunter]

the two sections of the unit have wedge shaped weights between them..
the unit exspands as the revs come up compressing the clutch plates but
you can still pull the clutch lever opening the clutch pack more than what the rekluse
unit can exspand giving a full manual clutch still...

http://i1244.photobucket.com/albums/gg563/petenz1/SAM_0003-1.jpg (http://s1244.photobucket.com/user/petenz1/media/SAM_0003-1.jpg.html)

http://i1244.photobucket.com/albums/gg563/petenz1/SAM_0007.jpg (http://s1244.photobucket.com/user/petenz1/media/SAM_0007.jpg.html)
Pretty slick! Thanks for the illustrated info. Someone on here will want one. Remember: "He who dies with the most toys, wins!".

[Ariel Red Hunter]

I was never a great rider, but like a lot of people, I was always fascinated by people who were great riders. Now we have this fantastic resource, you tube. I like to watch pre-65 trials on youtube. If you live in the Eastern or far Northwestern parts of the United States, you can learn a lot about handling a bike, off road, from these guys. Some of these guys are riding rigid frame motorcycles, and, if you watch closely, they are not at any real disadvantage. They use their legs for rear suspension. Some of the sections they ride through are tougher than you can imagine. Now when you ride trials, you loose points for a "dab", More points for "footing", and if you drop the little beastie, or kill the engine without being able to restart without footing, you loose five points, which means you've blown the section. When you listen to the Commentary, supposedly in English, maybe you will understand when he talks about points. Almost all of these bikes are running a 21 inch front, and an 18 inch rear, just like a Hawk. They are running trials tires, of course. Note how much these guys ride standing up. But that isn't all they are doing. They are shifting their weight, left and right, on the footpegs, as well as front to rear. If you like wheelies, you'll get to see the practical use of wheelies. So tune in, and enjoy. You might call this a College Education in riding the rough stuff.

[Ariel Red Hunter]

If you watched some of those trials videos, but were kind of overwhelmed with information, I found another one that may be even better for you guys. Google up to youtube-Mick's garden and especially watch the guy on the Honda twin-shock bike. You can learn a lot from just watching him, and then practicing, of course. Notice that these guys all have pretty low tire pressure, particularly at the rear. I was particularly impressed with this guys ability to lock the front tire, lift the rear, and move the rear any which way he wanted it. Gonna' take a lot of practicing to be able to do this. Gives you an excuse to ride, right? Another thing I noticed is most of these guys have quick-turn throttles (twistgrips). When those pulley type straight out twist grips came out, I bought one. Worked great FOR ME. Might not work so good for you. But some kind of quick turn twistgrip helps a bunch when you are riding slow, through the rocks, or whenever.

[pete]

Not normaly..

Trials bikes tend to use a 1/2 turn throttle not a 1/4 turn...
1/4 turn "quick action" makes the throttle action to twitchy
the smallest movment while turning going over what ever
and catapulted forward with a 1/4 turn...

The vid you watched Micks Garden is...
Mick Andrews a multi world trials champ... The Ossa MAR is the bike he developed
and won a couple world titles on..
MAR = Mick Andrews Replica

If yer want to see a trails rider... google Tony Bou
this guy isn't human... very very few mortals are even
close to that level..

one of the reasons vintage trials has be come so big
these guys are SO good that joe avarage can't come close
to getting around the courses these guys ride..

vintage trials old school bikes on old school courses
with the old rules...




.

[Ariel Red Hunter]

Not normaly..

Trials bikes tend to use a 1/2 turn throttle not a 1/4 turn...
1/4 turn "quick action" makes the throttle action to twitchy
the smallest movment while turning going over what ever
and catapulted forward with a 1/4 turn...

The vid you watched Micks Garden is...
Mick Andrews a multi world trials champ... The Ossa MAR is the bike he developed
and won a couple world titles on..
MAR = Mick Andrews Replica

If yer want to see a trails rider... google Tony Bou
this guy isn't human... very very few mortals are even
close to that level..

one of the reasons vintage trials has be come so big
these guys are SO good that joe avarage can't come close
to getting around the courses these guys ride..

vintage trials old school bikes on old school courses
with the old rules...




.I picked vintage trials to help people ride because they are more like the bikes we ride. The guys I remember riding Tiger Cubs in So. California used quick turn throttles, the guys with the big bangers used used the normal 1/2 turn twistgrip. Thanks for your input on this subject. I appreciate it.

[Ariel Red Hunter]

I forgot to mention that you should run the 17 tooth front sprocket because it is kinder to the chain, and leads to longer chain life. Try to make all the gearing changes you desire in the rear sprocket. So, let us say, you have the standard 50 tooth sprocket on the rear. With the 15 tooth front sprocket, the ratio is 3.33. With a 17 front, the ratio is 2.94 and change. An 11.7 boost in speed at the same rpm, assuming the engine can pull it. They claim 57-58 mph, as I recall. 57 mph plus 11.7 % boost comes up to about 64 mph, if my math is right. But what about low gear, you say. At an idle of speed of 1600, it increases about 1/2 mile per hour, to 4.5.

[Jmcgee]

Not normaly..

Trials bikes tend to use a 1/2 turn throttle not a 1/4 turn...
1/4 turn "quick action" makes the throttle action to twitchy
the smallest movment while turning going over what ever
and catapulted forward with a 1/4 turn...

The vid you watched Micks Garden is...
Mick Andrews a multi world trials champ... The Ossa MAR is the bike he developed
and won a couple world titles on..
MAR = Mick Andrews Replica

If yer want to see a trails rider... google Tony Bou
this guy isn't human... very very few mortals are even
close to that level..

one of the reasons vintage trials has be come so big
these guys are SO good that joe avarage can't come close
to getting around the courses these guys ride..

vintage trials old school bikes on old school courses
with the old rules...




.
I kinda like the Urban Trial videos, I want to learn to do that, Get into trouble around here though

[pistolclass]

Hey ARH check this out. My company had a bunch of electric vehicles come out to demonstrate there wares and it was supposed to include Zero Motorcycles. Alas, they did not show. I was bummed because they allowed folks to road test some very high end vehicles. ( a couple of porsches, an audi BMW... etc) There were even electric bicycles.

I noticed in there sales brochures a silly huge rear sprocket, the rear is 132T and the front is 25T. Why Pray-tell?

http://www.zeromotorcycles.com/zero-fxs/specs.php

[pete]

so they don't need a reduction box with the drag of gears/bearing/oil
Oil is the biggest HP robbing compont in a motor and the weight & space needed...
all that would shorten distance on a charge

[Ariel Red Hunter]

Hey ARH check this out. My company had a bunch of electric vehicles come out to demonstrate there wares and it was supposed to include Zero Motorcycles. Alas, they did not show. I was bummed because they allowed folks to road test some very high end vehicles. ( a couple of porsches, an audi BMW... etc) There were even electric bicycles.

I noticed in there sales brochures a silly huge rear sprocket, the rear is 132T and the front is 25T. Why Pray-tell?

http://www.zeromotorcycles.com/zero-fxs/specs.phpYeah, interesting. My first guess would be that they can get longer range by using a lightly loaded motor. This is a different kind of electric motor than what we are used to. A starter motor's Maximum torque is at stall, for instance. Note where this motor's peak torque is.

[Ariel Red Hunter]

Air boxes seem to fall into three classes. As a still air box, with an airfilter in it, a schnorkal that allows you to operate in streams so deep the water is higher that the engine cylinder head, as a still airbox cum intake sound muffler and air filter. Oh yeah, as an ornament on certain China bikes intended for dual sport use because one is supposed to be on there. The schnorkal type is almost always used only on military motorcycles. Now, inn the days of my youth, these were metal boxes that held a round paper element filter in the best examples, or had woven wire air filters that were aptly described as only for keeping gravel and small, low flying birds from being ingested into the engine. Oh, and I forgot the ones which had no filter of any kind, and were only supposed to keep mud and rocks out, while insuring that the engine got still air. Still air is more important than you might at first think. All kinds of carburetion problems occured with airflow coming over the cylinder head, around various frame rails, and other items hung wherever convenient during assembly at the factory. We used to coat the interior of those airboxes with grease in order to trap some of the dust coming in, and overloading the air filter.

[Ariel Red Hunter]

The Hawk air box is designed to quieten intake noise, and hold an air filter. Unfortunately, the air is pretty restricted getting into the air box. Motocheez has a video on modifying the intake of the box by opening up the area so that the air can get in easier and faster. I think it would be educational to watch that video. I wouldn't put the hardware cloth in the box unless you have a real bad mouse problem. With the intakes opened up, you now have what is called a still air box. Next decision is the air cleaner. It doesn't really matter if you choose a K&N tapered round filter with a sponge around it, or put in some good quality square filter where the stock one resides. But if you ride where it's wet, I would not reccomend a paper filter. And I would move the crankcase breather line out of the air box, and put a PCV valve in the line, installed so that air can get out of the crankcase, but cannot get back in. This has a couple of benefits besides keeping the filter clean. It reduces crankcase pressure, which is beneficial to keeping the seals from leaking, and it reduces air pumping losses. It also reduces oil misting, resulting in less power loss. Don't forget to plug the hole where the crankcase vent line used to go in the air box.

[hertz9753]

I'm pretty sure the Hawk doesn't use a crankcase vent to the air box.

[Ariel Red Hunter]

I have seen many pictures of Hawks with a kink in the pipe/hose that goes between the air box and the carburetor. A kink disrupts the air flow, so try to get rid of it. I would try undoing the clamps on both ends of the pipe/hose, and see if you can get the kink out, if you have one. Next is checking how well the carburetor matches up to the cylinder head. It is important to have them both in line, and with no step going from one to the other. Do not polish the head's inlet tract. You actually get a better flow if you leave it alone. Now about carburetors. The one that comes with the bike works OK, it is just hard to get jets for it. That's why many have gone to the Mikuni VM-26. But if you want to stick with the Keihan that came with the machine, you should check out Motocheez's video on how to modify the carburetor so you can change jets. If you choose to go for a Mikuni VM-26, there are two different kinds (at least). The easy ones to find on e-bay, and elsewhere have butterfly chokes for cold starting. The hard ones to find have no butterfly choke, but use an enriching circuit for cold starting. Because there is no butterfly choke, there is less airflow disturbance in the carb. This is better. Potentially, a little more horsepower, assuming it is jetted correctly. A little more horsepower, gained here and there can add up to a difference. In other words, cleaning up the intake tract all the way from where it begins to the head is the trick. Not just one thing, but all of them working in harmony in order to get a greater weight of fuel/air mixture into the engine is the answer.

[hertz9753]

It's plastic and that is how it is molded. It doesn't look so bad from the top.

[pete]

Do not polish the head's inlet tract. You actually get a better flow if you leave it alone.

In other words, cleaning up the intake tract all the way from where it begins to the head is the trick.




glad yer cleared that up....






.

[Ariel Red Hunter]

It's plastic and that is how it is molded. It doesn't look so bad from the top.Yours doesn't look all that bad. I've seen a lot worse on this forum.

[Ariel Red Hunter]

glad yer cleared that up....






.I try to write stuff that everybody can understand. That's why I used two sentences to say the same thing in two different ways.

[hertz9753]

The Hawk also doesn't have a clamp to the air box, it is glued to it.

[pete]

I try to write stuff that everybody can understand. That's why I used two sentences to say the same thing in two different ways.

one says Don't do it.... the other says Do it...




...

[Bruce's]

It is confusing to me too Pete .

[pistolclass]

Must be a yank thing. I got it.

[Ariel Red Hunter]

It is confusing to me too Pete .Did you really read it, or did you skim read it. Maybe it's my fault. One sentence means leave the cylinder head porting alone. The other sentence means work on smoothing the airflow from where it begins to the carburetor. And check the carb to head fit, no steps is what you want. Does that help?

[Bruce's]

I have read it ,and you clearly state do not polish the heads intake tract ,and near the bottom of the paragraph you clearly state the exact opposite to me ,cleaning up the intake tract all the way from where it begins to the head is the trick .In one sentence you say to clean it up is the trick ,the other sentence says don't polish it ,which at least to me ,is exactly how you clean up something like that .What is the difference between polishing an intake ,or cleaning one up to you ? to me ,it's the same thing ,but it appears you might have a different idea about it .Have you got any data from the Hawks you either did or didn't clean up the intake on for a comparison ?

[Jmcgee]

I have read it ,and you clearly state do not polish the heads intake tract ,and near the bottom of the paragraph you clearly state the exact opposite to me ,cleaning up the intake tract all the way from where it begins to the head is the trick .In one sentence you say to clean it up is the trick ,the other sentence says don't polish it ,which at least to me ,is exactly how you clean up something like that .What is the difference between polishing an intake ,or cleaning one up to you ? to me ,it's the same thing ,but it appears you might have a different idea about it .Have you got any data from the Hawks you either did or didn't clean up the intake on for a comparison ?

I have worked on heads a bit, NOT hawk heads but drag bike heads, and race car heads. with heads you look at the angles and flaws in the flow track. usually where the track turns down near the valve is the most restriction. you "massage" them and get rid of hard angles and open the flow up. Polishing to a mirror finish is what some consider polishing and it is a waste on the intake, most say you need a little turbulence so the gas and air stays mixed. Ive tried both ways and see no difference at all with the polish so why waste the time....

[Jmcgee]

Ok, I just read what he said, he is saying from the air box to carb to the head. at least that's what I understand from it.... and yes he is somewhat right but do the head too and it will get better flow if done correctly.

[Ariel Red Hunter]

I have read it ,and you clearly state do not polish the heads intake tract ,and near the bottom of the paragraph you clearly state the exact opposite to me ,cleaning up the intake tract all the way from where it begins to the head is the trick .In one sentence you say to clean it up is the trick ,the other sentence says don't polish it ,which at least to me ,is exactly how you clean up something like that .What is the difference between polishing an intake ,or cleaning one up to you ? to me ,it's the same thing ,but it appears you might have a different idea about it .Have you got any data from the Hawks you either did or didn't clean up the intake on for a comparison ?You think TO THE HEAD means go ahead through the head? Cleaned up, well I didn't clean up any Goldstar heads. But others polished the intake passage on their Goldstar heads, and all I can tell you is the dyno showed no advantage to a finely polished head. Now as to cleaning up intake tracks on heads, that is pretty much a holdover from the days of cast iron heads and cylinders in the case of flatheads. Foundry technique has really improved out of all recognition since WW 2. Improved step by step until now. The only head that I had that needed an experts touch was the one on my AJS 350, which , according to the flow expert I consulted (Jerry Branch), was not strangled on the intake side, but was suffering from extreme constipation on the exhaust side. I think the average guy is well counseled to leave the head alone. If you want to do head work on your engine, make sure you can buy another head, because it is not difficult to screw one up. Do you need to ask how I found that out?

[Ariel Red Hunter]

Ok, I just read what he said, he is saying from the air box to carb to the head. at least that's what I understand from it.... and yes he is somewhat right but do the head too and it will get better flow if done correctly.Yes, but getting better flow in the head is the problem. It takes a real expert with a flow bench to really do the job right. And don't forget a bigger intake valve with the right under valve head tulip shape all helps intake flow. But this whole thing is an expensive road to go on.

[Jmcgee]

Yes, but getting better flow in the head is the problem. It takes a real expert with a flow bench to really do the job right. And don't forget a bigger intake valve with the right under valve head tulip shape all helps intake flow. But this whole thing is an expensive road to go on.

Getting more flow in the head does not take a flow bench.... if you want modern day John Force flow yes, but old school drag racers done it by hand without a flow bench... bigger hole, smoother edges = more flow

[Jmcgee]

This is an old school air cooled single cylinder, you don't have to worry about matching the flow in the ports, you don't have to worry about hitting water jackets.

Now you can't get stupid with the die grinder but it can easily be done if you are partially competent with a die grinder (Dremel).
it's actually easy, look it up on google and youtube, with car heads it's basically the same thing. Open the hole a little, smooth the edges get flow.

if you get silly and remove too much and open a hole you can possibly ruin a head, but drag racers have used epoxy to reshape ports so if you don't hit the valve seat you could still save the head.

[Ariel Red Hunter]

Exhausting, this thread, Huh? But plenty of good opinions have been posted on here, and I want to thank everyone of you who have been involved in this thread. I once upon a time was a newspaperman, so I tend to think of my work here as a column, and responses to it as commentary. And all of you as readers. I think the exhaust side of the Hawk is where the biggest gains can be made. There are more manufacturing flaws in the stock exhaust system than can be believed. Once the exhaust valve opens, the first order of business is to get it out of the engine as quickly as possible. Start with what they are using for an exhaust gasket. Whatever it is made of, raggety bits of it hang out in the exhaust stream right at the joint between the head and the head pipe. First thing I would do about that is replace that gasket with a copper o-ring from a Honda 230. Next comes that head pipe. All the photographs of the inside of that pipe that I have seen are a gas flow disaster. Sloppy bubble gum welds on the inside of the head pipe cause turbulence in the exhaust gas flow. Turbulence in the exhaust pipe acts to restrict the gas flow. Next comes the catalytic converter. It is too small. And thus even more restriction in the exhaust pipe. I know why they put it there. They use less very expensive platinum that way. So, I would put a mandrel bent head pipe there to replace the stock one. Next comes the muffler. I don't know enough about the muffler because the pipe leading to it is so bad, I can't tell if the muffler is another restriction or not. But I would buy one of those complete exhaust systems, along with the copper o-ring gasket, and put it on. Now I would definatley plan to re-jet the carburetor, because with less back pressure, and improved flow, it will run too lean. You've already adjusted the valve clearances, I hope. Combined with the work you did on the intake side, it ought to be a runner.

[Ariel Red Hunter]

Restrictions in the head pipe do not just cause reduction of exhaust flow. It also raises the temperature of the exhaust valve, the head, and the oil temperature. Not good, huh?

So, let's review what we have either done, or at least thought about doing. The engine/transmission package, including air-box through muffler has been streamlined as much as we can in order to get a greater weight of fuel/air mixture through the engine per power stroke, or two revolutions. We have changed the front fork oil to the flavor of your choice. You have changed the brake fluid to D.O.T. 3 or 4. You have the tires on it, front and rear that suits your riding style, as well as the terrain you routinely ride on. You have installed rim locks so that you can run low air pressures off road. You may have even gone so far as to use co2 in the tires, because Pete told us how it allows low pressure off road, where the tires stay cool, but expands and raises tire pressure when the tires heat up, like on road riding. You keep your spokes tight. You check, and correct, if necessary, tire alignment. You watch very closely the swing arm bushings, which tend to go bad very quickly. When they go bad, a simple machine shop job on the swing arm lets you change to roller bearings. You have made sure that the front and rear axles and the swing arm bolt are well greased. You make sure that the motor mount bolts stay tight. Locktite really helps with this. Also brake caliper bolts need the same attention. That's all I can think of for now. M-r-r- a-ha-ha-ha.

[BlackBike]

Restrictions in the head pipe do not just cause reduction of exhaust flow. It also raises the temperature of the exhaust valve, the head, and the oil temperature. Not good, huh?

So, let's review what we have either done, or at least thought about doing. The engine/transmission package, including air-box through muffler has been streamlined as much as we can in order to get a greater weight of fuel/air mixture through the engine per power stroke, or two revolutions. We have changed the front fork oil to the flavor of your choice. You have changed the brake fluid to D.O.T. 3 or 4. You have the tires on it, front and rear that suits your riding style, as well as the terrain you routinely ride on. You have installed rim locks so that you can run low air pressures off road. You may have even gone so far as to use co2 in the tires, because Pete told us how it allows low pressure off road, where the tires stay cool, but expands and raises tire pressure when the tires heat up, like on road riding. You keep your spokes tight. You check, and correct, if necessary, tire alignment. You watch very closely the swing arm bushings, which tend to go bad very quickly. When they go bad, a simple machine shop job on the swing arm lets you change to roller bearings. You have made sure that the front and rear axles and the swing arm bolt are well greased. You make sure that the motor mount bolts stay tight. Locktite really helps with this. Also brake caliper bolts need the same attention. That's all I can think of for now. M-r-r- a-ha-ha-ha.

Spokes...check here :lmao: POW ! IMPALEMENT GOES THE INNER TUBE AT 50MPH .. man speaks the truth

[Ariel Red Hunter]

Brooklands was a race track built in a suburb of London, England. In the course of time, houses crept closer and closer to Brooklands. Noise! OMG! We must do something! So, in order to race there, some kind of muffler had to be put on the machines. Eventually, in order to be fair to everyone racing there, a standard silencer was designed, and, wonder of wonders, the bikes were actually faster with the muffler on than with a straight pipe. I don't see why you can't make one for your Hawk, if the spirit so moves you. So, think of a trapazoidal metal can, with the exhaust pipe going into the can at the lower front corner. It has been found that the exhaust pipe should stick into the can 2 inches. Now the most critical part. The volume of the can must be 6 times the swept volume of the engine. E.g. 1500cc's or a quart and a half. Next, the exhaust goes out the diametrically opposed corner, or, the upper rear corner. This pipe also goes in 2 inches, and comes out to a fishtail with many holes drilled in it. Perhaps the more astute of you have already figured that if you make that final exhaust pipe out of a short nipple, a little bigger than the inlet pipe, you could mount a spark suppressing screen, 4 - 6 inches long in there. Using the fishtail to screw it in or out. Be sure to coat those threads with that heat resistant permatex thread compound, to make it easy to unscrew it on demand. For you guys who have a tig or mig welder, this is pretty simple. You could even make it out of 1/8 inch aluminum, and pop rivet it together. Just use the marine type pop rivets as they have solid heads. I can hear it now "ARH has finally blown a gasket". "ARH is crazier than a bedbug with the clap."

[pete]

meany meany moons ago....
when I was racing Speedway TQ Midgets they bought in the 98db rule
The best way to quiten them down was use a V8 car muffler the big oval buggers..
there was no power lose as the volume of the muffer was more than able to flow
all the gases from a Suzuki GSXR 750...

they also tryed the same with the solos " speedway bikes" but that diddn't
fly as it is a international class with rules set in stone and with a 9 times world champ
reading them the riot act they backed down real fast...





..


..

[Ariel Red Hunter]

I just had a flash. If you used a Dremel type tool to cut out the sides of the fishtail, and either welded or pop riveted the spark arrester screen on the inside of the fishtail, you're spark arrester problems would be solved. What do you guys think of that idea?

[Jmcgee]

Tinkering, I found a massive restriction in the little "carb to head" intake runner, felt like 3/16 at the top that port match would open up for more flow.

[Ariel Red Hunter]

Tinkering, I found a massive restriction in the little "carb to head" intake runner, felt like 3/16 at the top that port match would open up for more flow.I wrote about that whole subject a few days ago, but I never specifically called out the intake runner. My bad, sounds like. You found this mismatch at the head end of the plastic runner?

[Jmcgee]

I wrote about that whole subject a few days ago, but I never specifically called out the intake runner. My bad, sounds like. You found this mismatch at the head end of the plastic runner?
I believe its aluminum,it is between the carb and the head. Where my jap bikes have rubber carb holders.

[Ariel Red Hunter]

I believe its aluminum,it is between the carb and the head. Where my jap bikes have rubber carb holders.Oh? Maybe they up-graded to aluminum. The earlier ones had a plastic (phenolic?) spacer, from what I've seen on various youtube videos.

[pete]

Oh? Maybe they up-graded to aluminum. The earlier ones had a plastic (phenolic?) spacer, from what I've seen on various youtube videos.


I think you are talking about the heat riser.... nylon block to help stop the heat from
the head migrating in to the carb body...
rubber intake boots , manifolds don't need them as the rubber works as a barrier...



...

[Ariel Red Hunter]

I think you are talking about the heat riser.... nylon block to help stop the heat from
the head migrating in to the carb body...
rubber intake boots , manifolds don't need them as the rubber works as a barrier...



...Yes, that's what I think as well. And you put it very well. A side benefit is that it makes the intake tract longer. I think some engines needed rubber intake boots in order to reduce or stop fuel frothing in the float bowl from engine vibration. Or so we were told.

[Weldangrind]

Tinkering, I found a massive restriction in the little "carb to head" intake runner, felt like 3/16 at the top that port match would open up for more flow.

Please show us.

[Jmcgee]

http://www.chinariders.raptorrefuge.com/picture.php?albumid=150&pictureid=759

Yep aluminum

[pete]

scribe a line around it remove the manifold... use a dremal or die grinder...
put a rag down the head & have a vacume cleaner sucking as you
grind it off..

Or if theres a lip on the other side in the other direction..
I may be possable the slot the mounting holes to centre the manifold
on the head....



...

[Jmcgee]

scribe a line around it remove the manifold... use a dremal or die grinder...
put a rag down the head & have a vacume cleaner sucking as you
grind it off..

Or if theres a lip on the other side in the other direction..
I may be possable the slot the mounting holes to centre the manifold
on the head....



...

The intake tube is what has the issue, I am going to pull it off and put Dykem on it, re install and use a hooked scriber to scribe it. then pull it off and grind it to the line.

[Ariel Red Hunter]

The intake tube is what has the issue, I am going to pull it off and put Dykem on it, re install and use a hooked scriber to scribe it. then pull it off and grind it to the line.Looking at your picture, is that a casting flaw in there, or just a stain of some kind in the intake tube.

[Jmcgee]

Not sure yet, didn't feel it and the camera works better than my eyes at that angle. I'm going to pull it off later tonight and get some more pics of it and the work as I do it.

[Jmcgee]

Two aluminum parts are fused together with a rubber isolator between them. the flaw that's in the pic was in the rubber.

[Ariel Red Hunter]

Two aluminum parts are fused together with a rubber isolator between them. the flaw that's in the pic was in the rubber.Well, I'd buy a new inlet tube, myself. Or make a new one. Unless you can find a substance to fix it with that absolutely won't come loose.

[Jmcgee]

https://www.amazon.com/GOOFIT-Performance-Filter-150cc-Scooters/dp/B017DA541E/ref=sr_1_2?s=automotive&ie=UTF8&qid=1477147071&sr=1-2&keywords=42mm

thinking about this filter, the cover will protect it from the elements while increasing airflow.

[pete]

looks very restrictive



...

[hertz9753]

It looks like a double bagger and it wouldn't work for the intended purpose. :hehe:

All kidding aside, You really should put the air filter in a box or have something to restrict the hot air coming from the engine and exhaust...

[Jmcgee]

looks very restrictive



...

Even if it as restrictive as the original airbox. at least I can access it... that is my major issue, why they made it like that did stumps me
:hmm: These last couple of post should have been posted in the magician issues, not hawk talk. sorry guys my bad.

[Ariel Red Hunter]

Even if it as restrictive as the original airbox. at least I can access it... that is my major issue, why they made it like that did stumps me
:hmm: These last couple of post should have been posted in the magician issues, not hawk talk. sorry guys my bad.No, I think that issues with the engine, gearing and intake-exhaust systems should be here because these issues go across all C/B's using this engine. So, you aren't bad!

[Jmcgee]

Has anyone converted to a cable choke? I think I'm going to attempt it. any experiences may be helpful.

[Ariel Red Hunter]

Has anyone converted to a cable choke? I think I'm going to attempt it. any experiences may be helpful.How long a time do you have to keep the choke on? Bike should be ready to go with no choke, if you start it on choke, then pull on your gloves and put your helmet on. Then push the choke off, and ride.

[Jmcgee]

How long a time do you have to keep the choke on? Bike should be ready to go with no choke, if you start it on choke, then pull on your gloves and put your helmet on. Then push the choke off, and ride.

On the magician it is a little more difficult to get to the choke, It is tucked up in there and on the wrong side of the carb for ease of access, that's why I need a cable. I wish it was as easy as the hawk looks.

[BlackBike]

On the magician it is a little more difficult to get to the choke, It is tucked up in there and on the wrong side of the carb for ease of access, that's why I need a cable. I wish it was as easy as the hawk looks.

Just find something off the shelf somewhere at hd or ace hardware and rig it up

http://www.jackssmallengines.com/jacks-parts-lookup/part/mtd/7460614a?gclid=cjwkeajwv7habrcsxfrjkjpnrwgsjaa45qa 29he4wilpewrqjfb6j6womrddeeao7ah0gxt-j7z6dhoc5hfw_wcb

You get the idea $6 at agri supply

http://www.oregonpartsdirect.com/images/60-039.jpg

[Jmcgee]

Just find something off the shelf somewhere at hd or ace hardware and rig it up

http://www.jackssmallengines.com/jacks-parts-lookup/part/mtd/7460614a?gclid=cjwkeajwv7habrcsxfrjkjpnrwgsjaa45qa 29he4wilpewrqjfb6j6womrddeeao7ah0gxt-j7z6dhoc5hfw_wcb

You get the idea $6 at agri supply

http://www.oregonpartsdirect.com/images/60-039.jpg

Of course, I know I need a cable with a barrel end, a cable clamp, and a couple brackets, I can look and find or make what I need. just thinking if someone else already did it, it would save time and $ following their steps. My Dad always said a true genius does not just learn from his mistakes, he learns from everyone else's.

[95C1500]

ILL post a thread about this too but I need an answer. I've got mine torn apart right now (you can read my hawk thread for the reason and all of that) and I need the little gasket that sits inside the centrifugal oil filter cap. I can't find any in eBay, RPS hasn't gotten back to me, and the local dealer that said they HD it, gave me one that was the right shape but was way too big for the cap.so there's two sizes apparently. Is there another engine (one with readily available pars) that would use the same gaskets? Same centrifugal oil filter different engines, etc... Please help, I'm ready to get this thing back on the trails.

[Ariel Red Hunter]

ILL post a thread about this too but I need an answer. I've got mine torn apart right now (you can read my hawk thread for the reason and all of that) and I need the little gasket that sits inside the centrifugal oil filter cap. I can't find any in eBay, RPS hasn't gotten back to me, and the local dealer that said they HD it, gave me one that was the right shape but was way too big for the cap.so there's two sizes apparently. Is there another engine (one with readily available pars) that would use the same gaskets? Same centrifugal oil filter different engines, etc... Please help, I'm ready to get this thing back on the trails.The only help I can give you is to repeat what a sales rep told me over the 'phone at APSC. "We carry a Lot of Hawk parts, and what we don't have, we can order in from China". If you want to call them, their phone # is 731-632-3222

[Jmcgee]

ILL post a thread about this too but I need an answer. I've got mine torn apart right now (you can read my hawk thread for the reason and all of that) and I need the little gasket that sits inside the centrifugal oil filter cap. I can't find any in eBay, RPS hasn't gotten back to me, and the local dealer that said they HD it, gave me one that was the right shape but was way too big for the cap.so there's two sizes apparently. Is there another engine (one with readily available pars) that would use the same gaskets? Same centrifugal oil filter different engines, etc... Please help, I'm ready to get this thing back on the trails.

My first thought is gasket paper at the auto parts store. I'm not sure what the gasket looks like but http://www.autozone.com/sealants-glues-adhesives-and-tape/gasket-material they proly got the material

[BlackBike]

Jmcg..spoken like a true Chinese engineer:hehe:

[Weldangrind]

Of course, I know I need a cable with a barrel end, a cable clamp, and a couple brackets, I can look and find or make what I need. just thinking if someone else already did it, it would save time and $ following their steps. My Dad always said a true genius does not just learn from his mistakes, he learns from everyone else's.

I can tell you from my quads that the detent must be removed from the choke lever (which is very simple). The choke lever has a barrel slot and hole in it to accept a barrel-end cable. The choke door has a small spring built in that will help the choke fully open, as you slide the lever towards the open position. I think you'd be better off to find a purpose-built choke lever and cable from a quad or dirt bike, rather than a generic item.

[Weldangrind]

ILL post a thread about this too but I need an answer. I've got mine torn apart right now (you can read my hawk thread for the reason and all of that) and I need the little gasket that sits inside the centrifugal oil filter cap. I can't find any in eBay, RPS hasn't gotten back to me, and the local dealer that said they HD it, gave me one that was the right shape but was way too big for the cap.so there's two sizes apparently. Is there another engine (one with readily available pars) that would use the same gaskets? Same centrifugal oil filter different engines, etc... Please help, I'm ready to get this thing back on the trails.

To expand your search criteria, I believe that part to be the same as an XR200.

[Ariel Red Hunter]

So, I have been thinking about cdi controlled ignition timing. The only information I have found on the Hawk's cdi says that it has retarded ignition until about 1200 rpm. Then it jumps to maximum advance. I cannot find any information on whether the ignition fires every time the piston reaches the TDC area, or every other time. If it fires on every stroke, that presents a problem. Why? Because if it is, it is firing the mixture that rushed in to the engine when the exhaust pulse created a momentary depression in the cylinder during the valve opening overlap period. And, if it is firing at that time, there will be a pressure wave going not just out the exhaust pipe, but the intake as well. This will disturb cylinder filling, obviously. If we find that it is not firing at tdc of every revolution of the engine, then we only have to concern ourselves with the spark advance. Does anyone out there know the answers to these two questions?

[Mudflap]

It fires every revolution. What was the other question?

[pete]

If the pick up is on the flywheel it fires every time the piston is at TDC
if the pick up is on the cam it fires every second time...
most bikes infact just about all these days fire a spark every stroke
there is no issue at all with it...
both my Yamaha's & the Honda run a waist spark system...

4 cyclider motors only have 2 coils with 2 leads of each coil..
one coil to 1 & 4 cyclinders.. the other to 2 & 3 cyclinders
so one plug is fireing on the exhaust stroke..
never been a issue in the 50 odd years or more they have been doing it..





.

[Mudflap]

On most of these CG clone engines the spark advance at idle is 15 degrees and tops out at 35 degrees at 3500 RPM.

[Ariel Red Hunter]

[QUOTE=pete;234754]If the pick up is on the flywheel it fires every time the piston is at TDC
if the pick up is on the cam it fires every second time...
most bikes infact just about all these days fire a spark every stroke
there is no issue at all with it...
both my Yamaha's & the Honda run a waist spark system...

4 cyclider motors only have 2 coils with 2 leads of each coil..
one coil to 1 & 4 cyclinders.. the other to 2 & 3 cyclinders
so one plug is fireing on the exhaust stroke..
never been a issue in the 50 odd years or more they have been doing it...Quote

2016 - 50 1966? The 1960's BSA twins were running waste spark, so that part is right. But they were re-building engines left and right because of overheated pistons. They changed midway in the model year to spark every other stroke, and the problems went away. Harley-Davidson ran waste spark on their engines from at least the 1930's on with no trouble.

[Ariel Red Hunter]

On most of these CG clone engines the spark advance at idle is 15 degrees and tops out at 35 degrees at 3500 RPM.OK, the question is does it gradually increase between idle and 3500, or is it at 15 degrees, and then just jumps to 35 degrees.

[pete]

[QUOTE=pete;234754]If the pick up is on the flywheel it fires every time the piston is at TDC
if the pick up is on the cam it fires every second time...
most bikes infact just about all these days fire a spark every stroke
there is no issue at all with it...
both my Yamaha's & the Honda run a waist spark system...

4 cyclider motors only have 2 coils with 2 leads of each coil..
one coil to 1 & 4 cyclinders.. the other to 2 & 3 cyclinders
so one plug is fireing on the exhaust stroke..
never been a issue in the 50 odd years or more they have been doing it...Quote

2016 - 50 1966? The 1960's BSA twins were running waste spark, so that part is right. But they were re-building engines left and right because of overheated pistons. They changed midway in the model year to spark every other stroke, and the problems went away. Harley-Davidson ran waste spark on their engines from at least the 1930's on with no trouble.

you do realise the year is 2016 .... don't yer... with all these new metals & alloys now...aswell as all the new casting /forging processes...

As far as BSA goes...Sounds like they need the japs to make there pistons as they got it RIGHT from the start.... diddn't need decades to fumble around... and were able to make use of the tecnolagy of the day unlike the british companys.. who just let the motorcycle devalopment stagnate till the Japs breathed new life into it...
By that time there days were numbered.... copying the kawasaki GPZ900 was the only thing that saved Triumph... a big gamble that payed off for them...

Another little snipit for yer.... The LAST BSA's sold was the BSA Bushman.... was infact a
Yamaha AG100 farm bike only sold in 3rd countrys...
The mighty BSA were forced to go cap in hand to the Japs in there last days.

Google it..... The truth is out there...




.....

[Ariel Red Hunter]

[QUOTE=Ariel Red Hunter;234764]

you do realise the year is 2016 .... don't yer... with all these new metals & alloys now...aswell as all the new casting /forging processes...

As far as BSA goes...Sounds like they need the japs to make there pistons as they got it RIGHT from the start.... diddn't need decades to fumble around... and were able to make use of the tecnolagy of the day unlike the british companys.. who just let the motorcycle devalopment stagnate till the Japs breathed new life into it...
By that time there days were numbered.... copying the kawasaki GPZ900 was the only thing that saved Triumph... a big gamble that payed off for them...

Another little snipit for yer.... The LAST BSA's sold was the BSA Bushman.... was infact a
Yamaha AG100 farm bike only sold in 3rd countrys...
The mighty BSA were forced to go cap in hand to the Japs in there last days.

Google it..... The truth is out there...




.....I have heard rumors that, in fact, we have reached the year 2016.

[Ariel Red Hunter]

Yes, sports fans. I must plead guilty to my lack of attention to this column. One of the most important events in the known world is occuring right now. Yes! The Wold Series! It is important to me because my team has not won the World Series in 108 years. And their opponents have not won one since 1948! This is big doings, folks. So please excuse me for being distracted at this time this year.

[BlackBike]

Yes, sports fans. I must plead guilty to my lack of attention to this column. One of the most important events in the known world is occuring right now. Yes! The Wold Series! It is important to me because my team has not won the World Series in 108 years. And their opponents have not won one since 1948! This is big doings, folks. So please excuse me for being distracted at this time this year.

I want to watch ... but it's baseball so....

Especially great since the Cubs are in. Watching now Cubs up 7

Don't really have a dog in the hunt and was busy watching Dallas Cowboys beat Philly last Sunday night. How bout them 6-1 cowboys! :yay: (dak prescott "Mississippi State" boy!)

[pistolclass]

Baseball.... yawn

Football - Formerly cool but since they stopped respecting the national anthem I stopped watching that too.

ALMS racing (Now weathertech IMSA) Awesome sport. I can watch that all the time.

[Ariel Red Hunter]

Baseball.... yawn

Football - Formerly cool but since they stopped respecting the national anthem I stopped watching that too.

ALMS racing (Now weathertech IMSA) Awesome sport. I can watch that all the time.Harsh, pistolclass. Harsh!

[pete]

Yes, sports fans. I must plead guilty to my lack of attention to this column. One of the most important events in the known world is occuring right now. Yes! The Wold Series! It is important to me because my team has not won the World Series



The World series ?
So how meany counteys are playing in this WORLD series...
But I have heard of a single country club series being played lately....

better leave it there....


I myself are a rugby fan....( a New Zealender thats a rugby fan.... who would have thought..)
we are back to back world champs "real world champs" our national team hasn't been beaten for 18 matchs straight..these are all matchs against other countrys national teams..
we have won more rugby world titals than any other country...

....

[jimwildman]

Harsh, pistolclass. Harsh!

he isnt the only one, i havent watched a ball game in 3 years. some of the players dont respect this country, its laws, values. they dont deserve to be a roll model for our kids. and personally I have zero respect for them or the game..

In todays world sports seem so trivial, and act like a distraction for what is really going on.

mainstream sports are being ruined and in a hurry, i get more enjoyment watching the local kids play street hockey on the tennis courts in the playground.

[pistolclass]

When my family goes to a IMSA race most drivers invite my year 5 old son to sit in the car. Awesome bunch of professional. Last time we were at the track Jan Magnusson gave my son his hat. Try that with an NFL or MLB player today. 30 years ago maybe... today never.

[GeneralTso]

mainstream sports are being ruined and in a hurry, i get more enjoyment watching the local kids play street hockey on the tennis courts in the playground.

Being ruined? Ha, most of them are already crap. Google how many convicted felons are still playing in the NFL! How is that even allowed?? I know, I know, it's all about the $$$.$$!! And don't even get me started with the anthem crap...

That said, we live in Nashville area and my son did ice hockey for a while, he used to play at the rink the Predators trained at and what a good group of guys and franchise. It seemed like there was always a Pred or two around, the mascot used to show up to the rink every now and then and goof around with the kids and they had all sorts of Predator sponsored things going on. His high point was when the team got to skate out in the stadium, all suited up, between periods and take a couple shots on the goal.

[Ariel Red Hunter]

The World series ?
So how meany counteys are playing in this WORLD series...
But I have heard of a single country club series being played lately....

better leave it there....


I myself are a rugby fan....( a New Zealender thats a rugby fan.... who would have thought..)
we are back to back world champs "real world champs" our national team hasn't been beaten for 18 matchs straight..these are all matchs against other countrys national teams..
we have won more rugby world titals than any other country...

....Counties? I don't know. I think Cleveland is in Tuskarora County, Ohio. And Chicago is in Cook County, Illinois. The name has been shortened in the press. It is actually The Baseball World Series. There are players from a bunch of countries who play in the World Series. A bunch from the United States, some from Canada, quite a few from Cuba, Mexico, the Dominican Republic, Japan and Korea.

[culcune]

The World series ?
So how meany counteys are playing in this WORLD series...
....

Since the Canadian team lost to a US team, this series only had two US teams this year, but occasionally, there are Canadians in it.

[Ariel Red Hunter]

O.K., the World Series is over, and yes, the sun did come up the next morning. And Hell didn't freeze over, or so I have been informed. So, back to business. There is a very interesting series of videos on building a trials bike on youtube. Even if you are not interested in trials bikes, there is much to learn in this series of videos. How to and why one should bronze weld. HOW TO LACE-UP WHEELS THE EASY WAY! That one is worth a lot to some of you guys, me included. How to build a trials muffler (silencer). And all kinds of other arcane stuff. The site is Britannia Motorcycles, and the thread I found so interesting is building the BM 250 Trials Bike. He doesn't just tell you how to do this stuff, he shows you. Good thing, because he talks like he has marbles in his mouth, and his accent - well, he claims to be from Birmingham, but he doesn't mean Alabama.

[Ariel Red Hunter]

From reading forum threads on Hawks, I get the feeling that newer riders don't really understand the benefits of getting their cable runs as "sweet" as possible. Let's start with the clutch first. The less tight bends you have, the better it will work. A six inch longer cable can make a world of difference. There are cable "kits" that allow you to make your own cables up. This is a good skill to have, and once you have made one succesfully, it's like riding a bicycle - once you done it, you never really forget how to do it. When you adjust the clutch, start at the transmission end. It is imperitive to have some slack (about 1/8th inch) here to prevent clutch slippage, which leads to clutch over heating, which leads to clutch plate warpage, and that means having to rebuild the clutch. Then, up at the handle bar end is where you fine tune the clutch adjustment to get that 1/8th inch of free play at the handle bar clutch lever. The throttle cable, same story. Easy runs. No drag in the cable. Next to no slack in this cable, though. Just a leetle bit, Senor. In the Eastern USA, utterly flawless throttle control is directly related to rider satisfaction. And so is flawless carburetor tuning, because you need a perfectly smooth flow of power right from idle on up. Out west, people usually ride off road faster, because the terrain is so different, so low end throttle response is not so important.

Now gearing. If there is anything harder to gear than a dual-sport, I don't know what it is. You can either gear it for the highway, or the woods, or try to get both at the same time, but good luck on that. One way that I suggest is to carry a spare front sprocket with you and change gearing when you get to the woods. A 17-50 rear combo is not the ultimate, but maybe you can live with it. A 13 or 14-50 combo will work ok in the woods. Make up your chain and extra links of chain to make the switch. Be sure to take two extra master links, and a cranked link with you so you don't have to change the rear wheel position on the swing arm.

[pete]

Now gearing. If there is anything harder to gear than a dual-sport, I don't know what it is. You can either gear it for the highway, or the woods, or try to get both at the same time, but good luck on that. One way that I suggest is to carry a spare front sprocket with you and change gearing when you get to the woods. A 17-50 rear combo is not the ultimate, but maybe you can live with it. A 13 or 14-50 combo will work ok in the woods. Make up your chain and extra links of chain to make the switch. Be sure to take two extra master links, and a cranked link with you so you don't have to change the rear wheel position on the swing arm.


Or buy a bike with a wide ratio 6 speed box
and the gearing issue goes away...
They need to copy the TTR250 or DRZ250 motor
both super reliable , low maintance motors that yer
can reliy on to always get yer back home...



..

[Ariel Red Hunter]

Or buy a bike with a wide ratio 6 speed box
and the gearing issue goes away...
They need to copy the TTR250 or DRZ250 motor
both super reliable , low maintance motors that yer
can reliy on to always get yer back home...



.. Even being able to change the transmission gears that are in the Hawk to a wide ratio 5 speed would be a big plus.

[pete]

Even being able to change the transmission gears that are in the Hawk to a wide ratio 5 speed would be a big plus.

I think it would already have a wide ratio 5 speed....theres no reason to put a close ratio
in a duel sport & the motors they are copyed from have a wide ratio...
wide ratio is the norm for bikes used on the road...
just needs that 6th gear slightly higher..
The only duel sport bike I can think off with a close ratio box is
the Suzuki DRZ400.... but it was designed as a dirt only bike
then it was made road legal 2 years after it was first put in
production....And it's been it's main issue ever since for road use..
and it's a 5 speed... It's a good bike... but it could of been a great bike
with the right gear box..




...

[Ariel Red Hunter]

I think it would already have a wide ratio 5 speed....theres no reason to put a close ratio
in a duel sport & the motors they are copyed from have a wide ratio...
wide ratio is the norm for bikes used on the road...
just needs that 6th gear slightly higher..
The only duel sport bike I can think off with a close ratio box is
the Suzuki DRZ400.... but it was designed as a dirt only bike
then it was made road legal 2 years after it was first put in
production....And it's been it's main issue ever since for road use..
and it's a 5 speed... It's a good bike... but it could of been a great bike
with the right gear box..




...The internal ratios of the Hawk gear box are,
1 2.909
2 1.867
3 1.389
4 1.150
5 0.9545

Primary reduction is 3.33 to one.

[OUTERLIMITS]

It's plastic and that is how it is molded. It doesn't look so bad from the top.

Guys, just curious about this as I've seen this on a lot of Hawks. Just by looking at it, it looks like the intake tube should be pushed into the airbox so that groove mates up to the plastic of the airbox allowing a flange on both the inside and outside. Is that not possible with the way it's designed or the length of the tube?

Also, I'm wondering if anyone with a Hawk has tried to replace the paper air filter with some of the flat dual stage foam that Uni makes? Might have to cobble some kind of screen/frame to support it, but seems like it might be a good way to have the air filter be reuseable.

I'm interested in a pair of Hawks for my son and I, but the lack of response I hear from the distributor regarding parts is a bit of a red flag. I get that most online parts suppliers are not going to have any parts for this bike, but there should absolutely be a source from the distributor or manufacturer without buying 1000 widgets. Things like gaskets and seals etc are things they have on hand to build the bikes in the first place. If not, perhaps CSC has some parts that will directly replace from the TT250. They seem to have done a good job on their site listing parts and prices that they offer.

[Ariel Red Hunter]

Guys, just curious about this as I've seen this on a lot of Hawks. Just by looking at it, it looks like the intake tube should be pushed into the airbox so that groove mates up to the plastic of the airbox allowing a flange on both the inside and outside. Is that not possible with the way it's designed or the length of the tube?

Also, I'm wondering if anyone with a Hawk has tried to replace the paper air filter with some of the flat dual stage foam that Uni makes? Might have to cobble some kind of screen/frame to support it, but seems like it might be a good way to have the air filter be reuseable.

I'm interested in a pair of Hawks for my son and I, but the lack of response I hear from the distributor regarding parts is a bit of a red flag. I get that most online parts suppliers are not going to have any parts for this bike, but there should absolutely be a source from the distributor or manufacturer without buying 1000 widgets. Things like gaskets and seals etc are things they have on hand to build the bikes in the first place. If not, perhaps CSC has some parts that will directly replace from the TT250. They seem to have done a good job on their site listing parts and prices that they offer.I enquired of APSC, 234 North Maple Street, Adamsville Tennesee, 38310, about parts for Hawks. The salesman told me they have most of the replacement parts for the Hawk, and the ones they don't have they can get, directly from China. If you want to ask them about a specific part, or are interested in a motorcycle, try calling them at 731 632 3222. I would personally buy from them, as I want to support a dealer who carries parts. Might cost a $100.00 more to buy from them, but parts availability makes it a no brainer for me.

[Merlin]

Guys, just curious about this as I've seen this on a lot of Hawks. Just by looking at it, it looks like the intake tube should be pushed into the airbox so that groove mates up to the plastic of the airbox allowing a flange on both the inside and outside. Is that not possible with the way it's designed or the length of the tube?

Also, I'm wondering if anyone with a Hawk has tried to replace the paper air filter with some of the flat dual stage foam that Uni makes? Might have to cobble some kind of screen/frame to support it, but seems like it might be a good way to have the air filter be reuseable.

I'm interested in a pair of Hawks for my son and I, but the lack of response I hear from the distributor regarding parts is a bit of a red flag. I get that most online parts suppliers are not going to have any parts for this bike, but there should absolutely be a source from the distributor or manufacturer without buying 1000 widgets. Things like gaskets and seals etc are things they have on hand to build the bikes in the first place. If not, perhaps CSC has some parts that will directly replace from the TT250. They seem to have done a good job on their site listing parts and prices that they offer.

Getting parts for any china bikes is the big problem. Of all the china bikes out now I would think the Hawk will be the easiest to get parts for. The importers (RPS) rep for the Hawk (Adam Rinkleff) is a member here and he is always ready to help Hawk owners get parts. I think you and your son will be fine. If you want to plate them for road use that might be a problem where you live. I would check with your DMV to see if you can register a Hawk in your state before you buy if you intend to road ride. If you want to ride on the road a better bet would be a Bashan bike as there DOT approved. A Brozz would be my first choice or if not that a Storm.

[OUTERLIMITS]

I enquired of APSC, 234 North Maple Street, Adamsville Tennesee, 38310, about parts for Hawks. The salesman told me they have most of the replacement parts for the Hawk, and the ones they don't have they can get, directly from China. If you want to ask them about a specific part, or are interested in a motorcycle, try calling them at 731 632 3222. I would personally buy from them, as I want to support a dealer who carries parts. Might cost a $100.00 more to buy from them, but parts availability makes it a no brainer for me.

Could not agree more. I think they also have a good deal on a two bike deal. I just don't want to have to go to some machine shop to have custom bearings made, seals, etc.

[OUTERLIMITS]

Getting parts for any china bikes is the big problem. Of all the china bikes out now I would think the Hawk will be the easiest to get parts for. The importers (RPS) rep for the Hawk (Adam Rinkleff) is a member here and he is always ready to help Hawk owners get parts. I think you and your son will be fine. If you want to plate them for road use that might be a problem where you live. I would check with your DMV to see if you can register a Hawk in your state before you buy if you intend to road ride. If you want to ride on the road a better bet would be a Bashan bike as there DOT approved. A Brozz would be my first choice or if not that a Storm.

It does seem to be the most prevalent bike out there right now, which is a good sign. Ours would be registered in AZ, via my brother. The good thing is that out where he lives if it can roll, it can be registered for street. Where I am in Ca, not so much.

[BlackBike]

http://therps.net/DB-Hawk.html

[Ariel Red Hunter]

http://therps.net/DB-Hawk.htmlOK, RPS has parts available. I may have to take out a mortgage on some prime Mississippi bottom land in order to buy very many.

[Jmcgee]

OK, RPS has parts available. I may have to take out a mortgage on some prime Mississippi bottom land in order to buy very many.

These parts may be a good business to get into, or at least stock up on. the new prez might just make prices skyrocket

[BlackBike]

OK, since we are totally going off through rails here's one
http://www.kiiitv.com/news/local/special-reports/special-report-bee-county-bigfoot/351915533

http://www.kiiitv.com/img/resize/content.kiiitv.com/photo/2016/11/14/beebigfoot_1479169915317_7022894_ver1.0.jpg?preset =534-401

[rojo_grande]

My cousin, Marron (brown) Grande from Bee County Texas :lmao:

Rojo

[Ariel Red Hunter]

My cousin, Marron (brown) Grande from Bee County Texas :lmao:

RojoYeah, I really liked Bee County, until I found out there are "Big Foots" there. I don't have anything against them, I just don't want to have to answer a lot of dumb questions from tourists looking for one. I guess I'll have to go a little further west, like to George West.

[Ariel Red Hunter]

I guess there is a difference between a wheelie and lofting the front wheel. I think of a wheelie as something done sitting down, at least to start, whacking open the throttle, and up it comes. On the Hawk, jetting issues have to be addressed and maybe the exhaust, as well. Lofting the front wheel is done standing up, feeding in some more throttle, and used for a couple of purposes, crossing a log the most obvious. Now, if you have trouble lofting the front wheel under full control, the placement of the footrests may be the problem. The footrests appear (to me) to be a couple of inches in front of the swinging arm pivot point on the Hawk. One way to find out if this is true is to cheat a little. Try using one of the regular footrests, and one of the passenger pegs. If I'm right, this will shift your weight back to about where the swing arm pivot point is. This will make lofting under control much easier, if I'm right. And, if I'm wrong, well you aren't out very much, right? Remember when you do this, not only is your weight further back, it is also an inch or so higher.

[pistolclass]

I have done a few wheelies with my hawk and find the toughest part of it (besides needed about 10 more HP) is the seat design. That hump thing makes sliding my position on the bike difficult. If I had my way on the Hawks seat design it would loose that hump/saddle thing and go more up the gas tank. On steep grades you want to be way up or back on the seat depending if you ascending or descending.

[Ariel Red Hunter]

I have done a few wheelies with my hawk and find the toughest part of it (besides needed about 10 more HP) is the seat design. That hump thing makes sliding my position on the bike difficult. If I had my way on the Hawks seat design it would loose that hump/saddle thing and go more up the gas tank. On steep grades you want to be way up or back on the seat depending if you ascending or descending.That's a different way of riding than I do (did). I always stood on the pegs, or crouched (half stood) to control the bikes. I have ridden bikes that would lift the front wheel easily with less than 2/3rds the horsepower the Hawk has. It is all in the balance of the weight, fore and aft. The one thing I dislike most about the Hawk is the style of seat it has. But it is the style everybody seems to want these days. And you can't sell a bike without that style, or so it seems.

[pistolclass]

going down very steep slope i like to hang my bum as far back in the seat as possible. that hump thing impedes this. When I'm climbing a steep and on the throttle I'm sitting on the gas tank. Perhaps it is habit from my old 2 stroke days when I weighed only 135 pounds.

how do others ride on steeps.... And I mean steep, folks from kansas need not respond :)

in CT we have some serious topography.

[hertz9753]

going down very steep slope i like to hang my bum as far back in the seat as possible. that hump thing impedes this. When I'm climbing a steep and on the throttle I'm sitting on the gas tank. Perhaps it is habit from my old 2 stroke days when I weighed only 135 pounds.

how do others ride on steeps.... And I mean steep, folks from kansas need not respond :)

in CT we have some serious topography.

I ride the same way when going downhill. Uphill I'm all over the place trying to find traction. When it's really steep I will make my own trail and usually run into something that I can't get through. I call it the lay over and back up and not a crash. If you slide or tumble down the hill and the bike comes looking for you it's a crash.

[BlackBike]

I ride the same way when going downhill. Uphill I'm all over the place trying to find traction. When it's really steep I will make my own trail and usually run into something that I can't get through. I call it the lay over and back up and not a crash. If you slide or tumble down the hill and the bike comes looking for you it's a crash.

I'm not that adventurous yet but you sure drew a good picture:wtf:

[hertz9753]

I was riding a 1974 Yamaha GT80 when I was really young and that bike was so slow I had to duck walk it over the top of some hills. When I was 14 I got a 1981 Honda XL185S. It had 16HP stock and weighed about 245 with gas. It felt like a rocket to me with 2 more HP and over 50lbs less than a stock Hawk

Not many pictures of a 1981 XL185 out there but the Hawk feels pretty close to XL after the mods for reducing weight and gaining a little more power and the forks similar for some reason...

[culcune]

Thanks for the photo--that bike has helped numerous Chinariders get aftermarket rear sprockets over the years for their enduros.

[Ariel Red Hunter]

I'm not that adventurous yet but you sure drew a good picture:wtf:BlackBike, I'm going to reccomend a youtube video for you to watch. It is a English motorcycle training film for dispatch riders. Dispatch riders had to ride all kinds of roads and off-roads in order to get the dispatch to the officer it was intended for. It is in 4 or 5 segments. It starts out assuming you don't know how to ride a motorcycle, but bear with it, as these guys learn how to handle those 16H Nortons in places you wouldn't (yet) take your Hawk. And how to get out of trouble too. I found it when I googled up Norton 16H.

[Ariel Red Hunter]

BlackBike, I'm going to reccomend a youtube video for you to watch. It is a English motorcycle training film for dispatch riders. Dispatch riders had to ride all kinds of roads and off-roads in order to get the dispatch to the officer it was intended for. It is in 4 or 5 segments. It starts out assuming you don't know how to ride a motorcycle, but bear with it, as these guys learn how to handle those 16H Nortons in places you wouldn't (yet) take your Hawk. And how to get out of trouble too. I found it when I googled up Norton 16H.Actually, I googled up youtube-norton16h. If you have a short attention span, only watch part 3. Otherwise, start at the beginning.

[BlackBike]

BlackBike, I'm going to reccomend a youtube video for you to watch. It is a English motorcycle training film for dispatch riders. Dispatch riders had to ride all kinds of roads and off-roads in order to get the dispatch to the officer it was intended for. It is in 4 or 5 segments. It starts out assuming you don't know how to ride a motorcycle, but bear with it, as these guys learn how to handle those 16H Nortons in places you wouldn't (yet) take your Hawk. And how to get out of trouble too. I found it when I googled up Norton 16H.

Sounds like something I would download at the flying J...free Internet. Just too expensive with att 4g to watch videos at home. I like to download video frome there. Have watched all 10 long way round episodes, all the races to places and 1 Motocheez "hawk gang" ride.

This is a good opertunitunity to tell my story I picked up last weekend.. on our ranch we have what we call work days. I shreaded for about 6 hours in the common areas and for lunch we had hot tamales, chili and chips etc. I was talking to an older guy that has been a part of our community and he told me that he finally sold his bsa 650 (1952 year model). He is 90 years old but strong as a horse and really only recently started to take it easy. He said in the 50's he was in the Navy for 4 years and one night he was going home along the highway. He came across a motorist that turned out to also be in the Navy and had run out of gas. He said that they chained the bsa to that car and TOWED THE CAR ABOUT 15 MILES to the nearest gas station. He said he remembers that he never got out of 2nd gear but it did it. More testament to those old English steeds.

[hertz9753]

I watched the video and they did the layover on the hill. For some reason I want to join WWII and ride a motorcycle right now.

[Ariel Red Hunter]

I watched the video and they did the layover on the hill. For some reason I want to join WWII and ride a motorcycle right now.Good, you got it to work. I hope that will help you in your more "adventurous riding". I hope you eventually watch the other two as well. A lot of good tips on riding on there. Especially on using the clutch. Lucky you, your bike is about 150 pounds lighter than what those guys were learning on. Yes, folding foot rests are wonderful - except when you've got to get back down a steep hill you couldn't climb!

[Ariel Red Hunter]

Sounds like something I would download at the flying J...free Internet. Just too expensive with att 4g to watch videos at home. I like to download video frome there. Have watched all 10 long way round episodes, all the races to places and 1 Motocheez "hawk gang" ride.

This is a good opertunitunity to tell my story I picked up last weekend.. on our ranch we have what we call work days. I shreaded for about 6 hours in the common areas and for lunch we had hot tamales, chili and chips etc. I was talking to an older guy that has been a part of our community and he told me that he finally sold his bsa 650 (1952 year model). He is 90 years old but strong as a horse and really only recently started to take it easy. He said in the 50's he was in the Navy for 4 years and one night he was going home along the highway. He came across a motorist that turned out to also be in the Navy and had run out of gas. He said that they chained the bsa to that car and TOWED THE CAR ABOUT 15 MILES to the nearest gas station. He said he remembers that he never got out of 2nd gear but it did it. More testament to those old English steeds.A 1952 BSA 650. When you see him again, ask him if it was called the "Golden Flash", and did it have plunger rear suspension.

[hertz9753]

Good, you got it to work. I hope that will help you in your more "adventurous riding". I hope you eventually watch the other two as well. A lot of good tips on riding on there. Especially on using the clutch. Lucky you, your bike is about 150 pounds lighter than what those guys were learning on. Yes, folding foot rests are wonderful - except when you've got to get back down a steep hill you couldn't climb!

https://youtu.be/Z23hqSyOEi4


https://youtu.be/SZ7FMGXlM9E


https://youtu.be/2igIno8tYh4

You right click on the video and left click on Copy video URL. When you want post the video here you right click and then left click on paste. I only post online with a computer because my phone makes me look like my ignition is retarded...

[Ariel Red Hunter]

https://youtu.be/Z23hqSyOEi4

You right click on the video and left click on Copy video URL. When you want post the video here you right click and then left click on paste. I only post online with a computer because my phone makes me look like my ignition is retarded...I think you explained all of that beautifully. The problem is - - I'm too stupid to understand it.

[Ariel Red Hunter]

I see that 2 of the three British WO films have been downloaded to various places here at C/R yesterday and today. I started Hawk Talk to get as much information as possible in one place, in order for people to have more success finding the info. I wish some one would help me out on this by downloading all three of them to this column. There is a lot of information in those videos, to help people all the way from "This is my first motorcycle" on up. I know the information is old, but I think 80% of it is still valid.

[hertz9753]

The power of the edit button. I also saw the other posts of those videos...

[Ariel Red Hunter]

The power of the edit button. I also saw the other posts of those videos...I know my computer is getting a little old, and maybe that's why I can't find the edit button on my keyboard.

[hertz9753]

The power of the edit button. I also saw the other posts of those videos...

I know my computer is getting a little old, and maybe that's why I can't find the edit button on my keyboard.

When you make a post the edit button is on the bottom right next to quote and it looks like a pencil. There is also the multi quote button labeled MQ. You click that on every post in a thread that you want to reply to and click on quote on the final one.

[Ariel Red Hunter]

Way back when, in the 1920's there were two main manufacturers of motorcycle carburetors in England, Binks and Amac. The Amac was a variable venturi carb, like the keihin and the mikuni, except it required two lever control. One control lever (on the handle bars) lifted the air controlling piston, and the other raised and lowered the needle. The Binks had a better idling circuit and used emulsion tube control of low end mixture. Amac was the larger company and bought out Binks so as to be able to use their patents. They changed the company name to Amalagated Carburettors, Limited. Amal for short. within a year or two, they were able to utilise the emulsion tube idea in order to have a one lever carburetor. Then three or four years later, someone came up with twist-grip control. So endeth the lesson for today.
So, I was going through some old notebooks I was going to throw away, when I came across my old tuning notebook for the Amal GP carb fitted to my BSA Gold Star. I was going through it when I had an "Oh yeah" moment. Some other tuner had told me, and I wrote it down, on a simple main jet test. He called it the Roll-Off Test. This simple little test will tell you where you are at, main jet wise. First, get the engine well warmed up on your way to your favorite low travel, but high gear road. Now get well up into the power band in high gear. Apply full throttle. Keep it going like this for 3-4 seconds so that the carburetor is settled in and the engine pulling hard. Now rotate the throttle back to 7/8ths of it's wide open position. The pecularity of these style carburetors is they will richen up for about a second when you do this. So, if you get a tiny power surge, your main jet is too lean, or small. If the engine staggers slightly, or has a hard hesitation ( a hiccup), it's too rich. Simple, huh?

[OUTERLIMITS]

Way back when, in the 1920's there were two main manufacturers of motorcycle carburetors in England, Binks and Amac. The Amac was a variable venturi carb, like the keihin and the mikuni, except it required two lever control. One control lever (on the handle bars) lifted the air controlling piston, and the other raised and lowered the needle. The Binks had a better idling circuit and used emulsion tube control of low end mixture. Amac was the larger company and bought out Binks so as to be able to use their patents. They changed the company name to Amalagated Carburettors, Limited. Amal for short. within a year or two, they were able to utilise the emulsion tube idea in order to have a one lever carburetor. Then three or four years later, someone came up with twist-grip control. So endeth the lesson for today.
So, I was going through some old notebooks I was going to throw away, when I came across my old tuning notebook for the Amal GP carb fitted to my BSA Gold Star. I was going through it when I had an "Oh yeah" moment. Some other tuner had told me, and I wrote it down, on a simple main jet test. He called it the Roll-Off Test. This simple little test will tell you where you are at, main jet wise. First, get the engine well warmed up on your way to your favorite low travel, but high gear road. Now get well up into the power band in high gear. Apply full throttle. Keep it going like this for 3-4 seconds so that the carburetor is settled in and the engine pulling hard. Now rotate the throttle back to 7/8ths of it's wide open position. The pecularity of these style carburetors is they will richen up for about a second when you do this. So, if you get a tiny power surge, your main jet is too lean, or small. If the engine staggers slightly, or has a hard hesitation ( a hiccup), it's too rich. Simple, huh?

Does this same principle apply to a PZ or Mikuni carb used on the hawk?

[Ariel Red Hunter]

Does this same principle apply to a PZ or Mikuni carb used on the hawk?Absolutely! That is why I put it on here. Both the Mikuni and the Keihin round slide carburetors are clones of the Amal design.

[2LZ]

The power of the edit button....

On a different note, depending on what PC I'm on, the edit button doesn't show up. It's true! Then, if it's there, sometimes it won't show the entire paragraph that I'd like to edit, just the first sentence or part of it.
It's weird...... I think my IT people at work are on to me. ;-)

[Ariel Red Hunter]

Must be getting close to winter, the number of posts has dropped for the last week or so. When I was in my forties, on our dairy farm in western Michigan, I somehow heard about a 500cc Triumph Trophy twin, high pipes and all. Three-hundred bucks later and it was mine. I used to take Sunday off, except for chores. So, after church and breakfast, I would ride all over that farm. Whole place totalled up to 600 acres, and a little less than half of it was woods. There were deer trails through the woods, and I used to ride them for a couple of hours on Sunday afternoons. Mucho fun. And those Triumph twins sounded so sweet without mufflers. I couldn't get too radical riding that bike, as I had cows to milk twice a day, plus normal farm work to do, so I couldn't risk getting injured. But I had a young friend "Party Time" Postma. He owned one of those 360 Yamaha's, and he rode like the wind, no cares, all balls. So I'm out doing little jumps and doing figure eights out in a hay field when he shows up. Yes I had just mowed and baled that hayfield during the week. Now I knew he was a better rider than me, or he just didn't worry about the consequences. After he cut a couple of hot laps on the Yamaha, I offered him the Triumph to ride. It had a good set of Dunlop Knobbies on it, and I had the carburetor just set up to really work. The carb. was an Amal Mono-Bloc, and those were really good carbs. So he asked me how do you ride it, and I told him it was heavier than what he was used to, so just kinda go with the flow. Very easy bike to ride fast, as long as you didn't try to get careless with it. So he rode it, faster and faster - man, that engine was really singing, and he had an ear to ear grin that was worth the price of admission alone. When he stopped by me, engine idleing as smooth as a hound dog drinking milk, he says "Wow, this thing is really fast, and s-o-o-o easy to ride!" Well he made my day, what else can I say. Thanks for the memory, Allen.

[Ghenghis]

I'll add a bit of info I read about intake spacer length. Says a lower geared quick revving motor does better with a shorter carb to head spacer length. The Hawk, mine at least, was geared far too low from the factory, it had 15/45 sprockets, I put a 17 on the front and I can tell zero difference in power, as in there was no loss of power, it made the bike far better to ride and greatly increased the top speed.

The 167FMM isn't a fast revving engine but it does make decent amounts of torque in it's mid range, so this is where we'd benefit most from our efforts to increase power, the 17/45 sprocket combo seems to do a good job of targeting this mid range power. My research says that a longer intake tube between the carb and head is exactly the type of setup you want for an engine that's a little slower revving. Since there is more mass of air/fuel flowing you get a better cylinder fill from that setup. Too long of a distance from carb to head and you'll get fuel pooling in the head. There's also some sciency bits, I'll quote them here:

The intake system on a four-stroke engine has one main goal, to get as much air-fuel mixture into the cylinder as possible. One way to help the intake is by tuning the lengths of the pipes.

When the intake valve is open on the engine, air is being sucked into the engine, so the air in the intake runner is moving rapidly toward the cylinder. When the intake valve closes suddenly, this air slams to a stop and stacks up on itself, forming an area of high pressure. This high-pressure wave makes its way up the intake runner away from the cylinder. When it reaches the end of the intake runner, where the runner connects to the intake manifold, the pressure wave bounces back down the intake runner.

If the intake runner is just the right length, that pressure wave will arrive back at the intake valve just as it opens for the next cycle. This extra pressure helps cram more air-fuel mix into the cylinder

Might be worth a shot to experiment with this. Also, the intake tube running up to the carb definitely benefits from keeping a uniform circumference throughout it's length. The Hawk airbox would seem to wreck any benefits gained from this as the tube opens up into a box. You'd be better off running the intake tube into the box and having a round style filter on the end of the tube, merely using the box to keep water/debris out, tossing aside the Hawk's lawn mower filter.

[hertz9753]

If you want a new a Uni Filter I have one or you could buy the K&N filter, seal it with grease on the bottom and sealing the top bracket is your choice.


http://www.knfilters.com/search/product.aspx?prod=33-2238&pkid=3985091&rw=1

[Ariel Red Hunter]

I'll add a bit of info I read about intake spacer length. Says a lower geared quick revving motor does better with a shorter carb to head spacer length. The Hawk, mine at least, was geared far too low from the factory, it had 15/45 sprockets, I put a 17 on the front and I can tell zero difference in power, as in there was no loss of power, it made the bike far better to ride and greatly increased the top speed.

The 167FMM isn't a fast revving engine but it does make decent amounts of torque in it's mid range, so this is where we'd benefit most from our efforts to increase power, the 17/45 sprocket combo seems to do a good job of targeting this mid range power. My research says that a longer intake tube between the carb and head is exactly the type of setup you want for an engine that's a little slower revving. Since there is more mass of air/fuel flowing you get a better cylinder fill from that setup. Too long of a distance from carb to head and you'll get fuel pooling in the head. There's also some sciency bits, I'll quote them here:



Might be worth a shot to experiment with this. Also, the intake tube running up to the carb definitely benefits from keeping a uniform circumference throughout it's length. The Hawk airbox would seem to wreck any benefits gained from this as the tube opens up into a box. You'd be better off running the intake tube into the box and having a round style filter on the end of the tube, merely using the box to keep water/debris out, tossing aside the Hawk's lawn mower filter.This is very true. When I wrote about Joe Craig (the man who was very responsible for Norton's death-grip on TT and GP racing for 20 years), I didn't get very far into the intake system length part of his dissertation. He spent years on a dynomometer testing everything you can imagine. You might want to go back through this column, Hawk Talk, and read what he had to say. Understand, from 1928 to sometime in the first third of the fifties, this is all he did. He was an engine man, and he only worked on one type of engine, what came to be known as the Norton Manx. The Manx was a single cylinder engine made for racing, in 350cc and 500cc sizes. All air-cooled singles share a certain heritage. We can learn much from other successful designs. I am going to try to find the "intake and induction factors" part of his interview, and print it up this afternoon.

[hertz9753]

http://www.ebay.com/itm/270761406708?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I can't remember who used that to mount a filter inside of the air box. He also used something else mount it to the carb.

[Ghenghis]

This is very true. When I wrote about Joe Craig (the man who was very responsible for Norton's death-grip on TT and GP racing for 20 years), I didn't get very far into the intake system length part of his dissertation. He spent years on a dynomometer testing everything you can imagine. You might want to go back through this column, Hawk Talk, and read what he had to say. Understand, from 1928 to sometime in the first third of the fifties, this is all he did. He was an engine man, and he only worked on one type of engine, what came to be known as the Norton Manx. The Manx was a single cylinder engine made for racing, in 350cc and 500cc sizes. All air-cooled singles share a certain heritage. We can learn much from other successful designs. I am going to try to find the "intake and induction factors" part of his interview, and print it up this afternoon.

I'm looking forward to reading that! I was building my own engines for my hot rod cars back when I was 18, I've done lots of things wrong and some right, it's all a learning process that's kept me interested.

One of the biggest surprises came from something I didn't think would make much difference, not nearly as much as it did. I had a 94 Firebird and my buddy had a 94 Camaro, both had the LT1 engine. We had previously taken our cars to the 1/4 mile track and ran them in complete stock form. Rather than buying a cold air intake my buddy decided we would build our own. He found the largest diameter tubing that would fit under the hood, 4" truck pipe, it did require us to shave a little plastic off the edge of the top radiator mount to fit them. The tube had a 90 degree bend halfway through it's length which worked perfectly, it cleared all the components and stopped at the bottom of the engine compartment, we then fit K&N filters to the end of the tube. We also removed or cut a circular hole in the plastic cover/splash guard so they could pull fresh air from under the car.

Now it was time to test them at the track again. There could have been temperature/humidity variations from the last time we went but it had only been 2 weeks, so those will account for some but should be marginal. My Firebird gained 3/10's of a second consistently over many passes, a nice result I was extremely happy with. My buddy's Camaro "it had much lower mileage than my Firebird" gained .5 seconds on every single run he made. I know it sounds unreal, we hardly believed it ourselves, but the numbers don't lie. They were still 14 second cars, but now they were in the low 14's.

Proof that a long consistent diameter intake tube with a good filter works wonders. Not too many bends though, ours had a smooth 90 degree transition. To this day if I tell people that story they don't believe it.

[Ariel Red Hunter]

I'm looking forward to reading that! I was building my own engines for my hot rod cars back when I was 18, I've done lots of things wrong and some right, it's all a learning process that's kept me interested.

One of the biggest surprises came from something I didn't think would make much difference, not nearly as much as it did. I had a 94 Firebird and my buddy had a 94 Camaro, both had the LT1 engine. We had previously taken our cars to the 1/4 mile track and ran them in complete stock form. Rather than buying a cold air intake my buddy decided we would build our own. He found the largest diameter tubing that would fit under the hood, 4" truck pipe, it did require us to shave a little plastic off the edge of the top radiator mount to fit them. The tube had a 90 degree bend halfway through it's length which worked perfectly, it cleared all the components and stopped at the bottom of the engine compartment, we then fit K&N filters to the end of the tube. We also removed or cut a circular hole in the plastic cover/splash guard so they could pull fresh air from under the car.

Now it was time to test them at the track again. There could have been temperature/humidity variations from the last time we went but it had only been 2 weeks, so those will account for some but should be marginal. My Firebird gained 3/10's of a second consistently over many passes, a nice result I was extremely happy with. My buddy's Camaro "it had much lower mileage than my Firebird" gained .5 seconds on every single run he made. I know it sounds unreal, we hardly believed it ourselves, but the numbers don't lie. They were still 14 second cars, but now they were in the low 14's.

Proof that a long consistent diameter intake tube with a good filter works wonders. Not too many bends though, ours had a smooth 90 degree transition. To this day if I tell people that story they don't believe it.I can well believe it, although I suspect you gained more from the cool air you were getting. Cooler air is more dense=more power.

[OUTERLIMITS]

I'll add a bit of info I read about intake spacer length. Says a lower geared quick revving motor does better with a shorter carb to head spacer length. The Hawk, mine at least, was geared far too low from the factory, it had 15/45 sprockets, I put a 17 on the front and I can tell zero difference in power, as in there was no loss of power, it made the bike far better to ride and greatly increased the top speed.

The 167FMM isn't a fast revving engine but it does make decent amounts of torque in it's mid range, so this is where we'd benefit most from our efforts to increase power, the 17/45 sprocket combo seems to do a good job of targeting this mid range power. My research says that a longer intake tube between the carb and head is exactly the type of setup you want for an engine that's a little slower revving. Since there is more mass of air/fuel flowing you get a better cylinder fill from that setup. Too long of a distance from carb to head and you'll get fuel pooling in the head. There's also some sciency bits, I'll quote them here:



Might be worth a shot to experiment with this. Also, the intake tube running up to the carb definitely benefits from keeping a uniform circumference throughout it's length. The Hawk airbox would seem to wreck any benefits gained from this as the tube opens up into a box. You'd be better off running the intake tube into the box and having a round style filter on the end of the tube, merely using the box to keep water/debris out, tossing aside the Hawk's lawn mower filter.

There are some spacers on the market to make that length effectively a bit longer. Would probably have to experiment to see what would work on the Hawk. Maybe that could solve two problems in that it seems like most of the pictures I've seen of the carb to air box boot that it's just a little short. There is what looks like a little groove in the air box boot that should normally fit into the wall of the air box, but in most pics I've seen the groove is on the outside the the mounting area just heavily slathered with sealant.

[Ghenghis]

I can well believe it, although I suspect you gained more from the cool air you were getting. Cooler air is more dense=more power.

Exactly. But our self-made CAI's performed far better than any manufacturer model I'd used previously.

[Ghenghis]

There are some spacers on the market to make that length effectively a bit longer. Would probably have to experiment to see what would work on the Hawk. Maybe that could solve two problems in that it seems like most of the pictures I've seen of the carb to air box boot that it's just a little short. There is what looks like a little groove in the air box boot that should normally fit into the wall of the air box, but in most pics I've seen the groove is on the outside the the mounting area just heavily slathered with sealant.


Yep, you can easily tell that was kind of a last minute fix. I like to imagine hearing that design conversation as a nearby observer, lots of fast gibberish I cannot understand, yet anyone would notice the tension in their voices, then an engineer walks in with a tube of black sealant, everyone nods their heads in approval... :)

[OUTERLIMITS]

Yep, you can easily tell that was kind of a last minute fix. I like to imagine hearing that design conversation as a nearby observer, lots of fast gibberish I cannot understand, yet anyone would notice the tension in their voices, then an engineer walks in with a tube of black sealant, everyone nods their heads in approval... :)

Yeah so maybe the proper fix is the one someone here did with a metal tube that connected to the carb via a rubber tube with clamps and then just clamped on a Uni pod filter inside the air box. You would still apply sealant around the air box joint, but at least having a perfect seal there would really not be all that important with a pod filter clamped to the tube. Plus those pod filters are pretty efficient and have a lot of surface area. I'm a huge fan of foam filters and Maxima FFT filter oil. The clean side of the filter in the air box tube has always been super clean on all my bikes when it has come time to clean the filter and I ride in a lot of dust.

[Ghenghis]

Yeah so maybe the proper fix is the one someone here did with a metal tube that connected to the carb via a rubber tube with clamps and then just clamped on a Uni pod filter inside the air box. You would still apply sealant around the air box joint, but at least having a perfect seal there would really not be all that important with a pod filter clamped to the tube. Plus those pod filters are pretty efficient and have a lot of surface area. I'm a huge fan of foam filters and Maxima FFT filter oil. The clean side of the filter in the air box tube has always been super clean on all my bikes when it has come time to clean the filter and I ride in a lot of dust.

Yes, this is exactly what I'm going to do. Allows you to keep the dynamics of a straight tube, or at least as straight as possible, sound control as it's enclosed in the airbox, which also keeps it out of the elements.

[OUTERLIMITS]

Does anyone know what the stock stator is rated at? I'm hearing the TT250 is 300 watts, which sounds like a lot, but I thought the two bikes had very similar engines save for the counter balancer on the TT.

[Merlin]

Does anyone know what the stock stator is rated at? I'm hearing the TT250 is 300 watts, which sounds like a lot, but I thought the two bikes had very similar engines save for the counter balancer on the TT.

If I remember right its 180 watts. I would love to upgrade my stator to a 300 watt ver if I could find the right part. :clap:

[OUTERLIMITS]

If I remember right its 180 watts. I would love to upgrade my stator to a 300 watt ver if I could find the right part. :clap:

Sounds like plenty for a bike this size. I know people want to power big lights and heated grips and all, but even a DRZ400 only has about 150. If it's a true 180, that seems pretty good. I'm guessing the 300 that the TT250 is claiming might be a little speculative.

[Merlin]

The 300 watts stator would let me run a 100 watt transceiver. (Long term plans)

[Ariel Red Hunter]

By the time I finally found the book, I was tired out enough to have to go to bed. You guys can laugh, but some day you too will be pushing toward your 80th birthday, so BACK OFF. Anyway, Joe makes the observation that the exhaust and intake are inter related. So I'm going to start there with his statement. "In a racing engine, the exhaust gases must be discharged so that the piston works against the minimum possible gas pressure. The kinetic energy of the gas must be utilized in such a manner as to produce the maximum negative pressure in the cylinder towards and at the end of the exhaust stroke. Use can thus be made of a large valve overlap to get the inlet gas column moving in readiness for the next filling stroke. It has been established that the combination of exhaust pipe length and diameter is important in achieving the best possible results, and that no one combination is equally efficient over the whole speed range of the engine." Kinda sad, huh? Jeez, Joe, are you trying to tell me this is not going to be easy? That I might have to do that most dreaded of all work, THINK? I'm horrified! "Usually a long pipe of small diameter is good for power at low rpm, while a short pipe of larger diameter is better for power at high rpm. It is necessary to compromise with a pipe diameter and length that will give the best results at the most used part of the engine speed range." Think about that statement the next time you look at the inside of the head pipe. See those sloppy welds in there? Look at all that bubble gum. Any wonder that a new exhaust system really makes a difference? So now I'm going to quote the question, put forth by the tech editor of The Motor Cycle magazine, which will help yu get in the flow of what Joe says: 'Is it not true that considerable induction pipe length and long valve opening periods are necessary in order to make full use of the phenomenon you have just described?' I'm going to pull out the answer for the 348cc engine, as it is closer to what we are using here. "In the 348cc Manx engine, the diameter of the inlet port is 1 1/8th inches, and the length from the mouth of the carburettor to the middle of the intake valve is 10 and 3/8s inches." In other parts of this article he talks about a 1 degree widening of the whole inlet tract as improving power even a little bit more, but that is easy to over do. And for your information, when I first read this article, 62 (I think) years ago, I thought aha, I'll just make a trumpet 4 inches long, and I will be Golden. Didn't work. Couldn't get the carb tuned right. So I made a spacer 4 inches long and my carb problems were over.
So, hopefully you guys can see how this whole thing is inter related. Ideally, you make or buy a free flowing exhaust system that has at least some extractor effect. Then adding an inlet pipe to move the carburetor farther from the head. When you find the right length, there will be a positive pressure wave of intake gas at the valve, just when it is opening. The time for all of this to occur is very short, so even an 1/8th of an inch in the length of the pipe will make a difference. You could purposely make it too long and then shorten it in 1/16 inch steps, until you find the sweet spot.

[Ariel Red Hunter]

Designing a good push rod engine, one that runs easy and tirelessly is much more difficult than designing an overhead cam engine. And Honda really did a job when they came up with this little number. Thanks to new aluminum alloys and much refined foundry technique, and modern machine tools, these are really magnificent little engines. Yes, if I was in charge of engine development over there, I'd build a thousand of these lil' darlins' stroked out to 240-250cc, and send them over here to see if American riders can tear them up. I'd send them a hundred at a time to RPS, with spare engines in the event one blew up. Before they left China I'd have tried to wear out a few on a dyno. I'd send them as soon as the first ones passed the dyno test. Then turn them loose on the American public. And see what you guys do to them. Be fun, huh?

[pete]

Only had one push rod motor MK3 Weslake..
was a great motor till the OHC motors came along
Jawa/Godden/GM... then it could no longer holds
it's end up...


..

[Ghenghis]

I've been reading more about intake runner length, air flow, air velocity, and how surface texture affects air flow. There are plenty of opinions out there, you've got to weed through them all.

One bit that had a contradiction to our thinking on intake runner length between the carb and valve may be plausible. This supposed highly reliable/intelligent source stated that the distance between the carb and intake valve and it's benefit from shockwave resonance had little to do with making more power until an engine reached 6500 rpm. Total length of the air intake system had more effect on an engine revving under 6500 rpm. The reason for this was air velocity, as air travels through a round tube it experiences less drag at the center of the pipe, so a longer tube will experience greater air velocity overall. The outer air near the walls acts as a bearing to reduce drag, at subsonic intake speeds you want a rough finish as this provides a more efficient laminar flow across it's surface, this would also keep fuel from attaching to surfaces along the intake since it will also ride along above this air bearing and stay suspended in the intake flow. Reducing any irregularities or mismatched surfaces after the carburetor will result in not only the best flow but a uniform air fuel charge on each cylinder fill.

I'd guess this is why all my old Holley carburetors released fuel into the air stream at the center.

If you decide to do any porting on the intake port do not touch the floor of the port unless it's to add texture to the surface or remove blemishes, lowering the port floor will slow down the incoming charge. Unshrouding the port ceiling around the intake valve stem will raise the efficiency of the total valve face area. If you could see from inside the cylinder looking up as the intake valve opened you'd see the intake charge coming in mostly from one side of the valve because of uneven flow above it's face in the intake port on most stock setups. This makes it harder to fill the cylinder, so power is reduced.

Some people dimpled their entire intake like the surface of a golf ball. Dimples on a golf ball are there to reduce it's wake as it moves through the air so they fly straight, a large wake causes irregular turbulence causing a sphere to change direction. Jury is out on that method, unsure if you'd see any difference over roughing up the intake surface, intake air isn't exactly moving around a sphere. I suppose you could dimple your choke plate... :)

Combustion chamber and exhaust ports do see a benefit from being polished or smooth, it reduces hot spots and resists carbon buildup, also, supersonic moving airflow is more efficient along a smooth surface. Keeping the heat in your exhaust flow results in a higher velocity which has a scavenging effect on the next exhaust cycle. Wrap those exhaust pipes and smooth out those burrs!

I'm tired now.

[pete]

[QUOTE=Ghenghis;2372

Some people dimpled their entire intake like the surface of a golf ball. Dimples on a golf ball are there to reduce it's wake as it moves through the air so they fly straight, a large wake causes irregular turbulence causing a sphere to change direction. Jury is out on that method, unsure if you'd see any difference over roughing up the intake surface, intake air isn't exactly moving around a sphere. I suppose you could dimple your choke plate... :)

Keeping the heat in your exhaust flow results in a higher velocity which has a scavenging effect on the next exhaust cycle. Wrap those exhaust pipes and smooth out those burrs!

I'm tired now.[/QUOTE]

It's called the "Magnus effect"... only comes into play when the sphere is spinning..
is why a tennis soccer player or baseball pitcher can turn the ball in flight...
it produces a low & high pressure area on opisite sides of the sphere .. high pressure side pushes the sphere into the low pressure side turning the sphere in flight.. also why muskets & canons had unrifled
barrels to stop the musket ball spinning 'turning in flight"
they used this force to power a ship... if intrerested google "flettener rotor"

nature knows best..... sharks have a rough skin for this very reason
it traps a thin layer of water that makes the shark very smooth & slipery..

exhuast wrap... hotter the exhuast gasses the thiner they are so they can travel
faster...





....

[Ariel Red Hunter]

It's called the "Magnus effect"... only comes into play when the sphere is spinning..
is why a tennis soccer player or baseball pitcher can turn the ball in flight...
it produces a low & high pressure area on opisite sides of the sphere .. high pressure side pushes the sphere into the low pressure side turning the sphere in flight.. also why muskets & canons had unrifled
barrels to stop the musket ball spinning 'turning in flight"
they used this force to power a ship... if intrerested google "flettener rotor"

nature knows best..... sharks have a rough skin for this very reason
it traps a thin layer of water that makes the shark very smooth & slipery..

exhuast wrap... hotter the exhuast gasses the thiner they are so they can travel
faster...





....Yeah, Pete, mentioning sharkskin explains the issue perfectly. That's why polishing the inlet tract in the head is a poor idea. Polishing inlet tracts was a big deal in the 1920's and 30's. They got better performance because the inlet tracts in those days were rough castings, so any smoothing of ports made a big difference. A pressure die cast alloy head is not the same thing as a sand cast iron head. Because, for cost reasons, and production numbers, they took great care in designing the die cast molds. When they ran these engines on the dynos, and then polished the ports, the polished port engines were always a little lower in output. Took a while to figure out why. This little engine has a really great die cast head. Actually all of the castings are a tribute to the foundryman's craft.

[Jmcgee]

http://www.eastwood.com/images/email_images/Porting_Guide.pdf

Ariel, you are correct, I was reading this, it states you want about an 80 grit finish on the intake, and a polished exhaust.

[Ariel Red Hunter]

http://www.eastwood.com/images/email_images/Porting_Guide.pdf

Ariel, you are correct, I was reading this, it states you want about an 80 grit finish on the intake, and a polished exhaust.Yes, and polish the combustion chamber too. Just don't over do it. Leave the old valves in the head in order to protect the valve seat while you are polishing.

[timcosby]

on a less serious note i was watching z nation the other night and the girl was riding what looked to be an older type hawk and if you watch real close the brake caliper switches sides of the wheel a couple times! to make the bike look like it was going in the right direction the editor had mirrored the scene which is like looking in a mirror. you could see the exhaust changed sides too.

[Ariel Red Hunter]

I mentioned before sweet running, tireless engines. For may years, motorcycles were compared to horses, which is probably where that phrase comes from. A sweet motor cycle is one where the parts all seem to work in harmony. You don't have to think about what to do, it virtually seems to read your mind, and responds to your every thought. Maybe the modern phrase for this is fly-by-wire. Now I, and many others who grew up in the west, were born to the saddle. At least of my generation. I'd probably ridden four or five different horses before I rode one where I had that eureka moment of understanding how wonderful that experience could be. And once you have experienced it, you look for horses that you can develop that feeling of oneness with. Makes it easy to ride. And you can maintain higher average speeds with such a mount. Suprisingley, motor cycles are much the same. I'd ridden other motorcycles that I had never had that feeling of oneness with until I got my Red Hunter. I never had that feeling on a Harley-Davidson, but now that I'm thinking about this, that may explain the mystique of the Indian, it was that kind of bike. Japanese bikes I have owned were marvelous mechically, but never had that kind of soul. If you had ridden a Speed Twin, you were never all that impressed with to 450cc Honda twin. There was nothing really wrong with the 450, it was just not as sweet as the Triumph. As wonderful as the Yamaha 650 twin was, it was never in the class of a Triumph Thunderbird, or a BSA Super Rocket. They just lacked that fly-by-wire feel. The Hawk is a bike that approaches that hallowed ground. You have to manipulate a few things, but you can get there, if you want. So don't just drive it, ride it.

[BlackBike]

good one arh.

[Ariel Red Hunter]

good one arh.Tnx!

[hertz9753]

https://youtu.be/tseg8gLeF3U?list=PLdg9fM1l28T3rt72rQBbwsnPxx8uA1Qx p


I thought you would enjoy that.

[Ariel Red Hunter]

https://youtu.be/tseg8gLeF3U?list=PLdg9fM1l28T3rt72rQBbwsnPxx8uA1Qx p


I thought you would enjoy that.Well, I enjoyed it, that's for sure!


edit: listening to mr obvious and the snowblower the second time through was even funnier!