I am trying to adjust the valve lash for both the intake and exhaust. First, I am not absolutely certain I've found TDC. I put my thumb over the spark plug hole, and when I feel air rushing out, I start looking for the "T" in the little window. I stop turning the motor counter clockwise right at the dash before the T. Now, the intake valve arm is loose to the touch and can be readily adjusted by loosening the nut. The exhaust arm is not loose to the touch at all, and there is no gap. I can loosen the nut and turn counter clockwise, but there always seems to be pressure from the valve, and I can never get a gap. I thought maybe I wasn't at TDC on the compression stroke, so I tried going around to the next time the "T" appears, but it's the same--no play in the arm, no gap, and if I turn the arm, it there seems to always be pressure from the valve. I did post a previous thread where I'm trying to figure out why this bike won't start (after hydro locking from a gunked carb that sent gas inside the engine.) So this is just one more puzzle. Oh, I was able to do a compression test which was within spec.

 

Well...while the timing mark should indicate TDC, another way is to stick a screwdriver in the plug hole and slowly turn the crank...when at it's highest point, that would be darn close to TDC...once you've got what you think is TDC I'd look at the timing marks...it may be possible you've got too much advanced/retarded timing...that would cause starting issues for sure.


Also...it looks like you can see the valves pretty well with those covers off...you mention the exhaust valve being tight...I'd make sure it's opening & closing by having someone turn the crank while you observe...if not moving it's stuck (most likely bent) and if stuck closed it will not allow the engine to fire (think plugged exhaust pipe) but would still give good compression readings...


Hopefully one of these suggestions starts yielding results...

 

Thanks, I'm not sure I understand "look at the timing marks". If the cylinder is at the highest point and there are no marks in the window, what do I do? I had my wife turn the crank and looked at the exhaust valve, and it did move. I found this in the repair manual, so maybe you don't always check it at the "T": "When the piston is at the Top Dead Center (T.D.C.) on the compression stroke, there should be clearance between the valve stem tips and their respective rocker arm adjusting screws. If there is no clearance, rotate the crankshaft counterclockwise one turn." If I rotate one turn, I'm pretty sure the T will not be in the window.

 

Think all this manual does is confuse people. Forget about "strokes or compression stroke" as all this does is confuse people even more so.. Turn the flywheel,look ONLY at the intake rocker arm. As the rocker arm goes down and starts to come back up(intake valve starting to close), slowly continue turning the flywheel until the tdc mark comes up. Then you can check the valve clearance on the intake and exhaust valve.

 

Thanks. Then something is really wrong with my exhaust valve. I tried it at "T" a couple of different places (turns), and the exhaust rocker arm was never loose or had gap. I could turn the arm with a small wrench, but it felt like it had pressure on it. The Intake was plenty easy to jiggle, and had a gap already.

 

Intakes are usually the ones that tighten up over time because the valves are softer than the exhaust valves,but either one can tighten up over time. Are you holding the square end of the adjuster screw when you try to loosen the lock nut? If not they can kinda fuse together and may be hard to loosen the nut. They make a holding/adjusting tool for this also,but you can use pliers,vice grips etc. If this isn't the problem,could be a rocker arm or valve problem. See if this video helps any at all.

 

Thanks, Tech. I can take off the nut, but there is no gap, and I can turn the arm (screw?), but the valve seems to press against it and no gap is formed. It's really weird.

 

If you can't loosen the adjuster screw enough(with out running out of threads) to get the required clearance,then something is definitely wrong..Here's another video. Should be as simple as what he's doing.

 

Yeah, I can take the nut off and turn the arm, but it never gets loose. I should be able to jiggle the arm like the intake valve, but it is always tight. Any idea what could be wrong?

 

Is the arm against the valve stem or is the keeper not holding and the spring is coming up past the keeper? Rotate in down off of top dead center and stuff some nylon rope in the plug hole. Then rotate it until it's tight against the valves. You can then take the arm and spring off without the valve falling down into the engine and check them.