Hawk Talk - Page 19

Ariel Red Hunter · 12-31-2016, 04:13 PM

Spokes haven't been talked about much lately on this forum. On the Hawk, anyway (and no doubt, others) the spokes are a little skimpy. No doubt, the real solution is to go with Buchanon spokes. But 80 bucks (or more) per wheel is a real bite in the a++. The stock spokes have to bed in to the rims and the hubs when the bike is new. But the secondary problem is that those skimpy spokes stretch with use. That's why you have to keep checking spoke tension. I like, maybe because that is what I've used for about 65 years, the plain little 3 to 4 inch long spoke wrench. Hard to over tension spokes with that short of a wrench, if you don't use a piece of pipe to make it longer. I pulled on those wrenches with two fingers. YMMV. I use middle "C" (piano) as the pitch I want to set them at. You "ping" them with the wrench, or a screwdriver. I would check the spokes before I ever rode the thing, if it was me. Ride the bike for the first time for a half hour or so, then put the bike on a center stand, and ping them again. If they've gone flat (like B-flat, or G or G-flat), tighten them again. For the first week repeat this process. Second week, check spoke tension twice a week. After they stop stretching, I'd check them once a week if you are riding every day. Or maybe every 15 hours, if you prefer to keep track of time that way. Do this and you may never have spoke failure.

Ariel Red Hunter · 01-01-2017, 11:40 AM

About valves. If your valves are adjusted too tight (the way a lot of them have left the factory), you risk overheating the exhaust valve. One of the ways a 700 degree (f) exhaust valve loses its heat is when it seats on the head. If the valve is adjusted too tight, it doesn't seat firmly enough in the head for the heat transference between the exhaust valve and the cylinder head that we need to have happen. Too lean a fuel mixture makes this problem even worse. Exhaust valves and seats get rough from the temporary welding of the valve to the seat. Back around the turn of the last century, gas engines quite often used what was called "Hot tube ignition" They had no electric ignition of any kind. But those engines ran at about 275 revolutions per minute. And they were really only single speed engines. Their governor was an "Automatic" intake valve. This system had a weak spring as the only control of the intake valve. When the engine got up to about 350 rpm, the intake valve couldn't close fast enough, so the engine "missed". The so-called "Hit or Miss" engine. But we don't want that kind of engine in our hawks, so make sure that exhaust vale is not set too tight. About .005 (American) is about right. Too loose and you lose valve overlap and duration and lift. Intake valves sould be at around .003. Not tighter. It takes longer to ruin an intake valve, but it can still be done.

Ariel Red Hunter · 01-03-2017, 11:39 AM

I suppose that the kiehin clone carburetor that comes with the Hawk, and a half dozen other motorcycles, can be made to work satisfactorily as long as you are not too fussy. Or, the argument "I'm not going to spend $30 to buy a carburetor for a 1200 dollar motorcycle." Hey, I understand that point of view. And, I might add, if you ride in such a way that you are at 1/2 throttle, or more, most of the time, it can be made to work very well. Now, in theory, the Kiehin is just as good as a Mikuni. But in fact, because parts like carb slides, jets, needles and so forth are so much easier to get for a Mikuni, I like it better. That's if you buy and install the 30 dollar Mikuni. Personally, I'd buy the 85 buck VM-26 because it has a starting enrichment circuit instead of a butterfly choke. The butterfly choke causes errant air currents egzactly where I don't want them. Because I AM fussy when it comes to carburation. I want that engine to pull like a freight train right from low idle right on out to peak revs, in the tallest gear it will pull, Although people get all excited by fuel injection, I'm not all that impressed with electronic fuel injection on a motorcycle. Works good on a car or pick-em-up truck, but really, those vehicles are just really appliances, like a washing machine, or a dryer. Riding a motor cycle is a whole different deal, really.

letsride · 01-03-2017, 11:54 AM

Quote:

Originally Posted by Ariel Red Hunter

About valves. If your valves are adjusted too tight (the way a lot of them have left the factory), you risk overheating the exhaust valve. One of the ways a 700 degree (f) exhaust valve loses its heat is when it seats on the head. If the valve is adjusted too tight, it doesn't seat firmly enough in the head for the heat transference between the exhaust valve and the cylinder head that we need to have happen. Too lean a fuel mixture makes this problem even worse. Exhaust valves and seats get rough from the temporary welding of the valve to the seat. Back around the turn of the last century, gas engines quite often used what was called "Hot tube ignition" They had no electric ignition of any kind. But those engines ran at about 275 revolutions per minute. And they were really only single speed engines. Their governor was an "Automatic" intake valve. This system had a weak spring as the only control of the intake valve. When the engine got up to about 350 rpm, the intake valve couldn't close fast enough, so the engine "missed". The so-called "Hit or Miss" engine. But we don't want that kind of engine in our hawks, so make sure that exhaust vale is not set too tight. About .005 (American) is about right. Too loose and you lose valve overlap and duration and lift. Intake valves sould be at around .003. Not tighter. It takes longer to ruin an intake valve, but it can still be done.

I once seen a hit or miss engine at a county fair. It was powering an ice cream churn. I stood there for about an hour watching that thing go. It was hard for me to wrap my head around just how the thing worked. I mean I know it is a simple engine. But being as I grew up wrenching on OHV engines, this thing seemed out of this world to me. Finally the owner of the ice cream stand came over and explained how it worked and a light bulb went off in my head. Really cool stuff. My wife thought I was bonkers, and said "yes honey its a motor, can we move on now?"

But for some reason I could stand there and listen to that thing go POP, WHEW WHEW, POP.

OUTERLIMITS · 01-03-2017, 12:00 PM

Quote:

Originally Posted by Ariel Red Hunter

I suppose that the kiehin clone carburetor that comes with the Hawk, and a half dozen other motorcycles, can be made to work satisfactorily as long as you are not too fussy. Or, the argument "I'm not going to spend $30 to buy a carburetor for a 1200 dollar motorcycle." Hey, I understand that point of view. And, I might add, if you ride in such a way that you are at 1/2 throttle, or more, most of the time, it can be made to work very well. Now, in theory, the Kiehin is just as good as a Mikuni. But in fact, because parts like carb slides, jets, needles and so forth are so much easier to get for a Mikuni, I like it better. That's if you buy and install the 30 dollar Mikuni. Personally, I'd buy the 85 buck VM-26 because it has a starting enrichment circuit instead of a butterfly choke. The butterfly choke causes errant air currents egzactly where I don't want them. Because I AM fussy when it comes to carburation. I want that engine to pull like a freight train right from low idle right on out to peak revs, in the tallest gear it will pull, Although people get all excited by fuel injection, I'm not all that impressed with electronic fuel injection on a motorcycle. Works good on a car or pick-em-up truck, but really, those vehicles are just really appliances, like a washing machine, or a dryer. Riding a motor cycle is a whole different deal, really.

I had read somewhere in here that both the Mikuni pilot and main jets from the VM26 actually fit the Stock PZ carb. Can anyone verify that?

chuck · 01-03-2017, 02:04 PM

Quote:

Originally Posted by Ariel Red Hunter

I suppose that the kiehin clone carburetor that comes with the Hawk, and a half dozen other motorcycles, can be made to work satisfactorily as long as you are not too fussy. Or, the argument "I'm not going to spend $30 to buy a carburetor for a 1200 dollar motorcycle." Hey, I understand that point of view. And, I might add, if you ride in such a way that you are at 1/2 throttle, or more, most of the time, it can be made to work very well. Now, in theory, the Kiehin is just as good as a Mikuni. But in fact, because parts like carb slides, jets, needles and so forth are so much easier to get for a Mikuni, I like it better. That's if you buy and install the 30 dollar Mikuni. Personally, I'd buy the 85 buck VM-26 because it has a starting enrichment circuit instead of a butterfly choke. The butterfly choke causes errant air currents egzactly where I don't want them. Because I AM fussy when it comes to carburation. I want that engine to pull like a freight train right from low idle right on out to peak revs, in the tallest gear it will pull, Although people get all excited by fuel injection, I'm not all that impressed with electronic fuel injection on a motorcycle. Works good on a car or pick-em-up truck, but really, those vehicles are just really appliances, like a washing machine, or a dryer. Riding a motor cycle is a whole different deal, really.

Ariel Red Hunter which mikuni vm26 (starting enrichment circuit) fit the Hawk,is it the vm26-606 one?and thus the jets for the the clone mikuni fit the real one? Thanks

Ariel Red Hunter · 01-03-2017, 07:29 PM

Quote:

Originally Posted by chuck

Ariel Red Hunter which mikuni vm26 (starting enrichment circuit) fit the Hawk,is it the vm26-606 one?and thus the jets for the the clone mikuni fit the real one? Thanks

Yes it is. But it is a spigot mount carb. Not a real problem, but there is a flange mount vm-26 with a starting enrichment circuit. I just can't remember the number of it.
P.S. I can not find the flange mount version of the VM26. Mikuni does sell a spigot mount to flange mound adapter, and I have seen them from time to time on e-bay. I would buy the VM26-8074, as it has both a idle air mixture screw, AND an idle speed screw. The VM26-606 has no idle speed screw.

hertz9753 · 01-03-2017, 08:57 PM

Is that the power jet carb?

Ariel Red Hunter · 01-03-2017, 09:13 PM

Quote:

Originally Posted by hertz9753

Is that the power jet carb?

No, these two numbers are for the models with a starting enrichment circuit. The power jet one is the TM28, which is a flat slide carburetor. The Mikuni flat slides cost more than some of their competitors, but have the real advantage of interchangable throttle slides. Several throttle cut-aways available, in other words. With the cheaper flat slide carbs., if you are too rich or too lean coming off of idle, you have to change the entire carburetor.

Ariel Red Hunter · 01-03-2017, 09:21 PM

Quote:

Originally Posted by OUTERLIMITS

I had read somewhere in here that both the Mikuni pilot and main jets from the VM26 actually fit the Stock PZ carb. Can anyone verify that?

Yes, I have read that the main jets will fit the PZ carb. But not the pilot jet. Both Mikuni jets have a different thread pitch than PZ carbs do. But the Mikuni main jet works, and the pilot jet doesn't.

hertz9753 · 01-04-2017, 06:12 AM

http://www.ebay.com/itm/26mm-Carb-PW...3D112023070837

http://www.ebay.com/itm/112023070837...%3AMEBIDX%3AIT

My head hertz.

Ariel Red Hunter · 01-04-2017, 06:58 AM

Quote:

Originally Posted by hertz9753

http://www.ebay.com/itm/26mm-Carb-PW...3D112023070837

http://www.ebay.com/itm/112023070837...%3AMEBIDX%3AIT

My head hertz.

Yes, I know how you feel. The OKO flat slide is one of the ones that do not have different size throttle cutaways. If it's too lean, go to the next smaller carb. If it is too rich, go to the next larger carb. I don't much like that idea. But the price is very nice. OKO's use kiehin jets, which are available from a company in Maryland that takes selling and servicing OKO carbs very seriously.

Ariel Red Hunter · 01-04-2017, 07:41 AM

Well, that is how the air-fuel mixture is regulated coming off idle. Whether you have a "Power Jet" or not is controlled by throttle cutaway. The less the cutaway, the richer the mixture. Works like an accelerator pump, but from the other direction. One of the many reasons I like Mikuni carbs is because not only are jets easy to get, so are throttle cutaways. One of the advantages of the flat slide carburetor is an even bigger shot at throttle snap open. So if your Hawk feels puny when you first open the throttle, look into a smaller cutaway on the throttle slide. On the other hand, if you are getting a puff of black smoke, or the engine feels "Wooly", a larger cutaway is indicated. UNDERSTAND however, this is the last step (almost always) in dialing in a carburetor. Get the main jet and pilot jet right, needle position right, idle mixture dead nuts on, then fine tune, if neccessary, by way of the throttle cutaway. The final (rare) thing to change is the needle itself.

Kourosh · 01-07-2017, 02:54 PM

I just got my hawk, did the assembly all is going okay except the back brake pads are locked together, anyone know how to ease them? I've tried adjusting back brake lever tension via pedal, no results, If anyone knows what I have to do it would be appreciated. Thanks.

Ariel Red Hunter · 01-07-2017, 04:38 PM

Quote:

Originally Posted by Kourosh

I just got my hawk, did the assembly all is going okay except the back brake pads are locked together, anyone know how to ease them? I've tried adjusting back brake lever tension via pedal, no results, If anyone knows what I have to do it would be appreciated. Thanks.

They are hydraulically locked, in my opinion. You have an air bubble somewhere between the rear brake cylinder, and the caliper. You will have to bleed them. For what it's worth, if you are going to bleed them, you might as well change the brake fluid to an American or Canadian DOT 3 or 4 brake fluid at the same time. I'd do both the front and rear while you are at it. The front is relitively simple to do. The rear is harder, probably because the hydraulics are laid out in an almost straight horizontal line. Sincerely, ARH

12-31-2016, 04:13 PM	#271
Ariel Red Hunter Join Date: Jun 2016 Location: akwesasne, NY-13655 Posts: 2,220	Spokes!!! Spokes haven't been talked about much lately on this forum. On the Hawk, anyway (and no doubt, others) the spokes are a little skimpy. No doubt, the real solution is to go with Buchanon spokes. But 80 bucks (or more) per wheel is a real bite in the a++. The stock spokes have to bed in to the rims and the hubs when the bike is new. But the secondary problem is that those skimpy spokes stretch with use. That's why you have to keep checking spoke tension. I like, maybe because that is what I've used for about 65 years, the plain little 3 to 4 inch long spoke wrench. Hard to over tension spokes with that short of a wrench, if you don't use a piece of pipe to make it longer. I pulled on those wrenches with two fingers. YMMV. I use middle "C" (piano) as the pitch I want to set them at. You "ping" them with the wrench, or a screwdriver. I would check the spokes before I ever rode the thing, if it was me. Ride the bike for the first time for a half hour or so, then put the bike on a center stand, and ping them again. If they've gone flat (like B-flat, or G or G-flat), tighten them again. For the first week repeat this process. Second week, check spoke tension twice a week. After they stop stretching, I'd check them once a week if you are riding every day. Or maybe every 15 hours, if you prefer to keep track of time that way. Do this and you may never have spoke failure.
	0

01-01-2017, 11:40 AM	#272
Ariel Red Hunter Join Date: Jun 2016 Location: akwesasne, NY-13655 Posts: 2,220	Just a few words... About valves. If your valves are adjusted too tight (the way a lot of them have left the factory), you risk overheating the exhaust valve. One of the ways a 700 degree (f) exhaust valve loses its heat is when it seats on the head. If the valve is adjusted too tight, it doesn't seat firmly enough in the head for the heat transference between the exhaust valve and the cylinder head that we need to have happen. Too lean a fuel mixture makes this problem even worse. Exhaust valves and seats get rough from the temporary welding of the valve to the seat. Back around the turn of the last century, gas engines quite often used what was called "Hot tube ignition" They had no electric ignition of any kind. But those engines ran at about 275 revolutions per minute. And they were really only single speed engines. Their governor was an "Automatic" intake valve. This system had a weak spring as the only control of the intake valve. When the engine got up to about 350 rpm, the intake valve couldn't close fast enough, so the engine "missed". The so-called "Hit or Miss" engine. But we don't want that kind of engine in our hawks, so make sure that exhaust vale is not set too tight. About .005 (American) is about right. Too loose and you lose valve overlap and duration and lift. Intake valves sould be at around .003. Not tighter. It takes longer to ruin an intake valve, but it can still be done.
	2

01-03-2017, 11:39 AM	#273
Ariel Red Hunter Join Date: Jun 2016 Location: akwesasne, NY-13655 Posts: 2,220	Carbies I suppose that the kiehin clone carburetor that comes with the Hawk, and a half dozen other motorcycles, can be made to work satisfactorily as long as you are not too fussy. Or, the argument "I'm not going to spend $30 to buy a carburetor for a 1200 dollar motorcycle." Hey, I understand that point of view. And, I might add, if you ride in such a way that you are at 1/2 throttle, or more, most of the time, it can be made to work very well. Now, in theory, the Kiehin is just as good as a Mikuni. But in fact, because parts like carb slides, jets, needles and so forth are so much easier to get for a Mikuni, I like it better. That's if you buy and install the 30 dollar Mikuni. Personally, I'd buy the 85 buck VM-26 because it has a starting enrichment circuit instead of a butterfly choke. The butterfly choke causes errant air currents egzactly where I don't want them. Because I AM fussy when it comes to carburation. I want that engine to pull like a freight train right from low idle right on out to peak revs, in the tallest gear it will pull, Although people get all excited by fuel injection, I'm not all that impressed with electronic fuel injection on a motorcycle. Works good on a car or pick-em-up truck, but really, those vehicles are just really appliances, like a washing machine, or a dryer. Riding a motor cycle is a whole different deal, really.
	1

01-03-2017, 08:57 PM	#278
hertz9753 Join Date: May 2016 Location: Bismarck, ND Posts: 868	Is that the power jet carb? __________________ 2015 and 3/4 RPS Hawk 250. Most people would call it a 2016 but the MCO didn't.
	0

01-04-2017, 06:12 AM	#281
hertz9753 Join Date: May 2016 Location: Bismarck, ND Posts: 868	http://www.ebay.com/itm/26mm-Carb-PW...3D112023070837 http://www.ebay.com/itm/112023070837...%3AMEBIDX%3AIT My head hertz. __________________ 2015 and 3/4 RPS Hawk 250. Most people would call it a 2016 but the MCO didn't.
	0

01-04-2017, 07:41 AM	#283
Ariel Red Hunter Join Date: Jun 2016 Location: akwesasne, NY-13655 Posts: 2,220	Why would I care about a throttle slide cutaway? Well, that is how the air-fuel mixture is regulated coming off idle. Whether you have a "Power Jet" or not is controlled by throttle cutaway. The less the cutaway, the richer the mixture. Works like an accelerator pump, but from the other direction. One of the many reasons I like Mikuni carbs is because not only are jets easy to get, so are throttle cutaways. One of the advantages of the flat slide carburetor is an even bigger shot at throttle snap open. So if your Hawk feels puny when you first open the throttle, look into a smaller cutaway on the throttle slide. On the other hand, if you are getting a puff of black smoke, or the engine feels "Wooly", a larger cutaway is indicated. UNDERSTAND however, this is the last step (almost always) in dialing in a carburetor. Get the main jet and pilot jet right, needle position right, idle mixture dead nuts on, then fine tune, if neccessary, by way of the throttle cutaway. The final (rare) thing to change is the needle itself. Last edited by Ariel Red Hunter; 01-04-2017 at 10:11 AM.
	0

01-07-2017, 02:54 PM	#284
Kourosh Join Date: Jan 2017 Posts: 1	I just got my hawk, did the assembly all is going okay except the back brake pads are locked together, anyone know how to ease them? I've tried adjusting back brake lever tension via pedal, no results, If anyone knows what I have to do it would be appreciated. Thanks.
	0