HAWK 250 Warm Engine hard to start "Sometimes" ???

[Hillbilly-06]

I searched and read a few things looking for some help. I didn't see any "Cured the problem info" but may not have read enough. My issue is that "Sometimes" after I been riding a few minutes and stop, to talk to a neighbor or maybe kill the engine for just a few minutes. When I try to Kick Start it again, it's really hard to start "Sometimes" once in a while it surprizes me and just fires right up, but not every time. Imagine stopping to get gas, and there you are in line at the pump, kicking the crap out of a good warm engine with no results. It's very agrivating to say the least. COLD STARTS are not tooo bad, it and seems to start easier Cold. Might I be a tad rich yet on the new Mikuni? On my Cold starts, choke on first kick, then off and a few kicks later it starts right up. HOWEVER it has a kind of a miss or skip in it until it warms up. Also it won't idle at all until it's warmed up. I have the idle set on a warmed up engine, but not sure why i'm having a re-crank issue once I been riding it. I'm still a newbie to these bikes, so any input would really help, thanks...
:hmm:

[JerryHawk250]

Have you check and adjusted the valve yet. If not, they are probably set too tight and when it warms up the valve stop sealing off causing compression lost.

[Hillbilly-06]

I haven't even looked at the Valves yet. It has 150 miles on it. I have never adjusted valves on a bike before, is there a good step by step thread here? i mean one that you would recomend? Also before I take something apart, do I need anything, like gaskets or special tools? I have a good feeler guage, but don't know yet if it has the correct size(s) to use on a bike, may have to take a look at it. If a gasket is needed, is it something I can trace out on a cork sheet and cut out myself or do I need some weird looking super thing paper thing?

[The_DJ_Remixer]

https://www.youtube.com/watch?v=RTpAcOuUf7w

[JerryHawk250]

The gasket is an O-ring type gasket that is reusable. No special tools needed. Motocheese will step you right through it.

[Hillbilly-06]

Thanks, the video is awesome, looks like an easy task to check and or adjust them.

[Wild Dog]

Just be aware that the guy in the video made two mistakes.
1)The valve lash should be set in 0.05mm to 0.08mm, not 0.05" or 0.04" I guess it's common mistake if you live in the US and you use " all day long.
2)The Valve adjustment must be done with a cold engine.

[Megadan]

Just be aware that the guy in the video made two mistakes.
1)The valve lash should be set in 0.05mm to 0.08mm, not 0.05" or 0.04" I guess it's common mistake if you live in the US and you use " all day long.
2)The Valve adjustment must be done with a cold engine.

The 'Merica specs for the Honda CG125 engine is .003" plus or minus .001" for both valves on a cold engine. Which essentially works out to a range of .05mm to .10mm.

I do believe in a video not long after this one he had re adjusted his valves to .003" intake and .004" exhaust, which is what many here run. I set mine to .0025" and .003" and am quite happy with it.

[Wild Dog]

The 'Merica specs for the Honda CG125 engine is .003" plus or minus .001" for both valves on a cold engine. Which essentially works out to a range of .05mm to .10mm.

I do believe in a video not long after this one he had re adjusted his valves to .003" intake and .004" exhaust, which is what many here run. I set mine to .0025" and .003" and am quite happy with it.

I guess it makes sense for the American market because .05mm to .08mm translates: .0196" to .0314"

[Ariel Red Hunter]

The 'Merica specs for the Honda CG125 engine is .003" plus or minus .001" for both valves on a cold engine. Which essentially works out to a range of .05mm to .10mm.

I do believe in a video not long after this one he had re adjusted his valves to .003" intake and .004" exhaust, which is what many here run. I set mine to .0025" and .003" and am quite happy with it.Yes, you get a hair more duration with your valve clearances. I have recommended .003 inch inlet, .004 inch exhaust before because it is a safe number for engine break-in. I can think of no reason not to go a thousandths tighter on both valves after a thousand miles. But if I did that, I'd re-check my valve clearances more often. You may think a thousandth one way or the other doesn't matter, but a thousandth can be like 4-6 degrees on the quietening ramps....ARH ;)

[Wild Dog]

Yes, you get a hair more duration with your valve clearances. I have recommended .003 inch inlet, .004 inch exhaust before because it is a safe number for engine break-in. I can think of no reason not to go a thousandths tighter on both valves after a thousand miles. But if I did that, I'd re-check my valve clearances more often. You may think a thousandth one way or the other doesn't matter, but a thousandth can be like 4-6 degrees on the quietening ramps....ARH ;)

According to the owner manual of my bike, if you set them to .05 mm you should check the valves every 1000 km (620 miles) and if you set them to .08 mm you can go as far as 4000 km (2480 miles) before you have to check them.
But for my taste .08 mm is too noisy.

[culcune]

Get hold of NZbrakelathes...he will sell you a valve tool set direct from China.

[Megadan]

Yes, you get a hair more duration with your valve clearances. I have recommended .003 inch inlet, .004 inch exhaust before because it is a safe number for engine break-in. I can think of no reason not to go a thousandths tighter on both valves after a thousand miles. But if I did that, I'd re-check my valve clearances more often. You may think a thousandth one way or the other doesn't matter, but a thousandth can be like 4-6 degrees on the quietening ramps....ARH ;)

I check my valves at every oil change just as a habit. I also pull and check the plug and go over my spokes and bolts, check the steering stem and a quick wheel bearing check via wheel wobble test. I call it a "maintenance day," and it is a good way to spend a couple of hours just making sure everything is good to go. At the rate I ride, it's usually once a month.

Get hold of NZbrakelathes...he will sell you a valve tool set direct from China.

Yeah, it's not necessary, but it makes adjusting the valves a heck of a lot easier/quicker. It also comes with some extra gaskets and feeler gauges for a very reasonable price. Worth it in my book. :tup:

[Hillbilly-06]

I finally got around to Adjusting my Valves. I had to wait on my nieghbor to barrow a good set of feeler gauges, my set didn't go down far enough, it stopped at .008, so bummer, I waited a few days till he was around and got a good set from him.
It was a very simple proceedure after watching Motocheeze videos and drinking a few beers.
My bike cranks right up every time now and I can let it actually warm up just sitting there by itself and walk away from it. Pefect on the first try, they were too tight, and I went with the .004 and .005 adjustments. It made a huge difference not only in cold starts, but in how smooth the bike seems to run. THANKS to everyone that helped, and if that Motocheeze guy is on here, Great videos dude... Thanks for everything.

[dpl096]

I finally got around to Adjusting my Valves. I had to wait on my nieghbor to barrow a good set of feeler gauges, my set didn't go down far enough, it stopped at .008, so bummer, I waited a few days till he was around and got a good set from him.
It was a very simple proceedure after watching Motocheeze videos and drinking a few beers.
My bike cranks right up every time now and I can let it actually warm up just sitting there by itself and walk away from it. Pefect on the first try, they were too tight, and I went with the .004 and .005 adjustments. It made a huge difference not only in cold starts, but in how smooth the bike seems to run. THANKS to everyone that helped, and if that Motocheeze guy is on here, Great videos dude... Thanks for everything.

Congratulations..... When it's done correctly and the motor purs with a happy tappy valve it sure boosts the confidence to tackle other issues..

[SecondHandHawk]

Hi all.
My hawk is used and a project in work.
Was wondering if anyone knew what the actual compression of the hawk 250 is supposed to be.
My valves are set correctly. The motor runs great and reliable. But I suspect some compression loss/blow by

I have read other older threads but no one replied to my comment. One past reply stated 170-180 psi.

Thanks for any info.

[Megadan]

There is no official number, but the CG125 that this motor is based off of ran the same basic compression ratio and Honda states 170psi. Give it a bit of leeway for obvious potential variables and 160-170psi is going to be good. Anything 120psi or over means it will run fairly healthy, and 100psi or less - bad. This is a cold test with the throttle wide open.

[SecondHandHawk]

Thank you for the fast reply.
Thanks for the info about cold check and WOT.

I'll check mine tomorrow afternoon.