I bought a used 96 Rm250 decent bike had issues when i got it. it was said to be in good riding condition needing a few things.(couldnt test ride it due to michigan snow). it was leaking coolant so i pulled the head thinking it was blown up only to notice the inner head O-ring wasnt put in. And after fixing that noticed the utter lack of power. the power valve wasnt hooked up, fixed that as well. All simple and easy. So now its up and running and ridable. But it keeps gas fouling plugs BAD. It has a FMF pipe i checked my jetting already and its to specs according to the FMF website (170 main, 55 pilot air at 1 1/2 turns out). i know gas mixture doesnt cause this but ive got it at 40:1. im just stumped and lost. ive already bought gasket set for the motor. and new sprockets and chain due to worn out ones on it and chain skipping and it still rides as if skipping some so i think im gonna have to tear it down and rebuild the trans. Its becoming a nightmare and not an enjoyment as it should be.