[Joshy J]

Hello all, my first post, I just replaced valve seals, lapped valves, set clearance on a 1997 trx250, trying to make it stop smoking, burning oil, engine has 175LBS compression also have a 2000 foreman 400 seems to have good power but smokes and burns oil, My question is there anything besides piston&rings valve seals to make these machines stop smoking?, I never did the piston and rings in the 250, figured the compression was fine.

 

[Saber6]

If you do the valves its a good idea to do rings and hone the cylinder to remove glazing.

 

[tomgodd]

You ought to do the piston when you rebuild 1 part and not the other you seem to get more problems. I bought a 450r a few yrs ago and i rebuilt the head because it was bad. Well shortly after the piston went kerplunk and I just ended up putting a whole new rebuild on the motor. It ran fine after that and I sold it and the kid still is riding it with no trouble. with the age of that quad it probly has some hours so redo the piston and che the crank and stuff timing etc to make sure its good. Do it right the first time and youu will be happier. I wish I learned that on the 450. Also get a good service manual to walk you through it. GOOD LUCK!