rebuilt top end, bike revs like crazy!

[1998RM250]

oh man if i have to tear into the case, I might as well do a complete rebuild of the bottom end... I'm not going to run the bike anymore, I will order complete new gasket sets and try again. If not then it has to be the crank seals? What kind of mess am I getting myself into here, my buddy just split his case and hes having almost the same problem with his RM 250 since its been back togather.

 

[_JOE_]

It is CRITICAL that the case halves be PERFECTLY flat and free of imperfections. I've seen people just wing it and the cases don't seal worth a crap. If you're not confident you can do this paying someone who KNOWS how to do it could save you money.

 

[dekker]

I vote for a left side crank seal behind the flywheel.

 

[1998RM250]

I guess only time will tell... I'm going to pull the motor out and bring it down to have the cases split. All parts aside, what should I expect for labor doing this?

 

[gregorious77]

Why are you splitting the cases? try the crank seal first behind the flywheel.

 

[GarbatyA4]

Why are you splitting the cases? try the crank seal first behind the flywheel.

I agree. Check that first before splitting.

Try running the bike with the gas cap off see if that helps. Sounds like u are getting a lean condition like you're running out of gas.

Also, try using some carb cleaner around the carburater intake boot. If the engine starts to rev up that means u have an air leak.

Good luck.