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Valve Problem!!

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Well, i checked my valves today and of course with my luck both my exhasut valves zeroed out. Both my intake valves were perfect at .005. Now my concern is that i hope i checked them right because i used the method to find top dead center where you slowly trun the bike over untill you hear the decompression click and the cam marks look pretty alined to me although it was hard to see the right mark on the r becasue of the cam positioning. Now say by some change the bike wasnt at tdc then why were my intake valves perfect wouldnt they be off to? Please help me im really nervous i dont want a liflong hell with my bike ill go crazy

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Idk though becasue the bike is liek new ive only ridden it 4 times so idk if i did it wrong or not

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The exhaust valves aren't usually a problem. Check them again, and be sure you are at top dead center on the crank indicator.........

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You do know the intakes are on the RT side towards the carb standing on the ignition side of the bike.

I bet you're not checking them right. Be sure the cam lobes are facing to the rear of the bike.

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Hm, odd. You should definately check them again. Try setting TDC by using the method in the book and align the indicator marks. Just make sure that the cam lobes are facing toward the rear of the bike and slightly up. The rocker arm should be loose, just a little though. If you are not on the compression stroke, then the rocker will be VERY tight and will not move at all.

Like Throttlejockey said, the intake valves are the ones closest to the carb.

Good luck.

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thanks alot for all the help and confidence guys im going to give it a second try tomorrow and i now know my mistake because that rocker arm wouldnt budge...thanks again ill update you when i re-check them

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thanks..oh and does anyone know the actually size of that allen head for the cover on the right side case..i assume its probably about 10 mm becasue i tried an 8mm liek it said on the guide but its jsut a little bit too small

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well i checked them again today and the exhaust valves are still off..there not seroed but there like around .008-.009 and my intakes are fine....i alined up everything right too..im so mad becasue i havea four day weeked coming up where i can finally ride and my bikes gonna be in the shop..i hope i dont have a recouring problem..

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The exhaust valves don't go bad. You need to increase your shim size 4 steps on the exhaust if you measured correctly. They can be off from the factory. One of my intakes was off a little. After a reshim, its been going staying the same ever since. Why don't you shim them yourself. Its like an hour job the first time you do it. I can do it in half that now.

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The exhaust valves don't go bad.

Unfortunately they do go bad, not at the same rate as the intakes but as they get more time on the engines we are seeing an increasing number of riders with exhaust valves problems. Usually the damage shows up as deep pitting on the face of the valves. It looks like it's a result of carbon deposits getting trapped between the valve and the seat. Usually we are seeing this on engines with heavy deposits on the piston crown. Tough to say if it's the result of jetting, fuel or oil control at this point.

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Unfortunately they do go bad, not at the same rate as the intakes but as they get more time on the engines we are seeing an increasing number of riders with exhaust valves problems. Usually the damage shows up as deep pitting on the face of the valves. It looks like it's a result of carbon deposits getting trapped between the valve and the seat. Usually we are seeing this on engines with heavy deposits on the piston crown. Tough to say if it's the result of jetting, fuel or oil control at this point.

Rich: in terms of *just* oil control -- what would be your opinion/ranking/likelihood on the three following sources (and yes, it's just your opinion and I'm just curious):

== oil leaking past rings(didn't seat/seal well or worn-out)

== oil from crankcase vent/carb hose (this *can* be a signifcant source if you're wife is 5'2" and tips over a lot...)

== oil from over-oiled air filters (any brand filter oil)

== oil from No-Toil filter oil (due to it's lightness)

Thanks! - RandyB

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Randy - If I had to choose == oil leaking past rings / worn-out is where I would place blame based on what I've seen so far in these engines.

It's worth remembering that single ring pistons have marginal oil control at best, and when they wear out it only gets worse.

In race engines there is always going to be a balancing act played between oil control and minimal ring friction. Honda seems to be leaning in the low friction direction. I honestly believe radial gas porting should be standard on these pistons but apparently Honda feels otherwise.

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Randy - If I had to choose == oil leaking past rings / worn-out is where I would place blame based on what I've seen so far in these engines.

It's worth remembering that single ring pistons have marginal oil control at best, and when they wear out it only gets worse.

In race engines there is always going to be a balancing act played between oil control and minimal ring friction. Honda seems to be leaning in the low friction direction. I honestly believe radial gas porting should be standard on these pistons but apparently Honda feels otherwise.

Interesting! When we took Susan's 250X apart to replace the RH intake valve -- we decided to go the rest of the way and pulled the cylinder and piston as well.

== The cylinder looked great - still showing good, factory cross-hatching marks. And the cylinder skirts looked fine as well.

== The piston looked good albeit the oil/fuel/crud buildup on the top. We could detect no real signs of blow-by past the rings. Well.... as much as we could with a 1/4" deep piston skirt.... :devil: We also checked the piston to cylinder clearance - still well within spec.

== We then inserted the compression ring back into the cylinder and used the piston to push it down and get it square. It's clearance - while getting towards the large side - was still within spec.

But!! Holding the cylinder up to the light, we could actually see a bit of light leaking around the edges of the ring! :awww:

Indicating that it had lost it's "roundness" or temper and couldn't press out with enough force? :lol:

I know we're just theorizing here.... but food for thought, eh!

BTW, we ended up replacing the piston, rings, head and cylinder gaskets, intake valves and valve stem seals, and the exhaust pipe gasket because I only wanted to go in one time. :thumbsup:

We also re-routed the crankcase vent hose (connects to the valve cover) back into the top airbox opening and hooked it up to a Uni UP123 crankcase filter. (To eliminate putting engine oil into the carb and through the valves/piston.)

Cheers! - RandyB

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