Perfect compression with a messed up ring?

[feedmelies]

Is it possible for a piston ring to be messed up and still have perfect compression in both cylinders? Has anyone seen it?

 

I have looked at everything else I can think of but I still have hesitation on the top end of the power band on a bike that has previously kicked ass for the last year. And I haven

Edited October 22, 2007 by feedmelies

[blowit]

Is it possible for a piston ring to be messed up and still have perfect compression in both cylinders? Has anyone seen it?

 

I have looked at everything else I can think of but I still have hesitation on the top end of the power band on a bike that has previously kicked ass for the last year. And I haven

[feedmelies]

I am not afraid to take the top end apart. I am attempting to diagnose a problem in time to fix it before I go to Glamis Friday morning. If I start to take the top end apart then I will not be able to take the quad out this weekend. I am just hoping that the problem can be fixed a lot easier than opening the engine up.

 

Do you believe a messed up ring could cause a drop in performance in the top end of the power band, but allow the bike to act normally in the low end and mid range of the power band? That is my problem. Nothing else is noticeable, even sound from the cylinders.

 

Thanks for the insight.

[BenBB]

That smoke on one side more than the other, is it white? If it overheated it could have blown a head gasket/o-ring on that side and/or warped the head, and it could potentially only suck water when it's topping out the R's (and a static compression test may or may not indicate any problem). I'd check the coolant level in the radiator at the very least and make sure it's not gettin' burnt, if it's low and the smoke is real white, there's your problem.

 

Only other thing I can think of is the coil, a high-speed miss is a symptom of one starting to go. Of course that's assuming everything else is cool as far as jetting, good fuel, air filter, etc. I know how it sucks to miss a riding trip, but better that than (shudder) get towed back to camp behind a 4-stroke Hope for the head gasket that's an easy job :cool: