bent valve? although the clearances are usually pretty big initially. and that usually hangs them. but you could have floated it and bent it. id pull the valve and look carefully at the seat, and also the area where the valve sits on the seat. your valves can tell you alot. how about a broken valve spring or something like that? the marks matt is talking about is important.
jc
"tex, if your bikes a cheater, its not a very good one"
jc
"tex, if your bikes a cheater, its not a very good one"