Hawk Talk - Page 3

BlackBike · 08-24-2016, 11:41 PM

Delicious, nice work with weatherstripping.

LunaTech · 08-25-2016, 07:32 AM

@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 · 08-25-2016, 01:19 PM

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 · 08-26-2016, 01:01 AM

Quote:

Originally Posted by 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.

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.

LunaTech · 08-26-2016, 07:19 AM

Quote:

Originally Posted by hertz9753

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.

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

Ariel Red Hunter · 08-26-2016, 03:47 PM

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 · 08-26-2016, 04:04 PM

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.

Ariel Red Hunter · 08-26-2016, 05:38 PM

Quote:

Originally Posted by 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 · 08-25-2016, 08:41 PM

I bought the cheap 'fake' one carb.

Ichrisbot · 08-26-2016, 04:20 PM

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 · 08-26-2016, 05:05 PM

Quote:

Originally Posted by 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.

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?

hertz9753 · 08-27-2016, 01:57 AM

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 · 08-28-2016, 10:13 AM

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 · 09-02-2016, 02:01 AM

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.

Bruce's · 09-02-2016, 08:35 AM

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

08-24-2016, 11:41 PM	#1
BlackBike Join Date: Feb 2016 Location: George West, Texas Posts: 4,097	Delicious, nice work with weatherstripping. __________________ ***************************************** 2015 Bashan"Blaze" BS250GY-31 (DB-07K-250) GONE 2017 Suzuki V Strom 650 XT "We are all born ignorant, but one must work hard to remain stupid." ~Benjamin Franklin~
	0

08-25-2016, 01:19 PM	#3
Ariel Red Hunter Join Date: Jun 2016 Location: akwesasne, NY-13655 Posts: 2,220	Yet more Hawk talk. 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.
	3

08-26-2016, 03:47 PM	#6
Ariel Red Hunter Join Date: Jun 2016 Location: akwesasne, NY-13655 Posts: 2,220	Hawkie-Talkie 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.
	1

08-25-2016, 08:41 PM	#9
hertz9753 Join Date: May 2016 Location: Bismarck, ND Posts: 868	I bought the cheap 'fake' one carb. __________________ 2015 and 3/4 RPS Hawk 250. Most people would call it a 2016 but the MCO didn't.
	0

08-28-2016, 10:13 AM	#13
Ariel Red Hunter Join Date: Jun 2016 Location: akwesasne, NY-13655 Posts: 2,220	Hawkie-Talkie part 2 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.
	1

08-25-2016, 07:32 AM	#2
LunaTech Join Date: Jul 2016 Location: Jonesville, NC Posts: 136	@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.
	1

08-26-2016, 04:04 PM	#7
chuck Join Date: Sep 2015 Posts: 436	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.
	0

08-26-2016, 04:20 PM	#10
Ichrisbot Join Date: Sep 2015 Posts: 108	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.
	1

09-02-2016, 08:35 AM	#15
Bruce's Join Date: Apr 2015 Location: Sudbury ,Ontario Posts: 855	Holy crap Pete ,on this side of the world we certainly can't hunt or ride on a seal anymore .
	0