1997 RM250 problem with valves

[drewstair]

I did a top end on my RM250 last weekend. When I took out the piston it was damaged on one side. At the main exhaust port in the bottom of the cylinder the valve is actually sticking into the chamber, so the piston was hitting it.

The person who had it prior to the guy I bought it from apparently adjusted the power valves (the same as exhaust valves?) in order to de-tune the engine and take some power out of it. I can't see how to adjust these, though.

Is this a sign that the valves are just worn and need to be replaced or is there a way to adjust them to back it out of the cylinder? Thanks!

 

[drewstair]

Anyone? I am getting anxious to just pull everything apart again at this point. No good can come of that :)

 

[Studboy]

No adjustment should make the valve contact the piston. I would suspect that something is worn or loose.

 

[Rog]

Nothing should be contacting the piston, but to adjust powervalves theres a couple of powervalve caps on the left side (when sitting on the bike) of the cylinder. These need to be turned (from no tension) clockwise half a turn to tension the springs for the valves. Might pay to inspect powervalves after adjustment to see if they operate smoothly.

 

[drewstair]

Ok. Well I just ordered another gasket kit so I can tear it down next week and check it as I adjust them. I am hoping I don't have to replace the exhaust or governor assy. Bah. Thanks for the replies.