CRF's Only Forums

I've just bought a 2006 crf 250 x,I don't know any history of the bike so I've decided to rebuild the engine.
What should I be replacing? I know the valves give problems on these so I will change them.
Big end bearing seems ok but should I change it just to be safe? What about main bearings,transmission bearings etc.
Any advice would be appreciated.

Welcome to CRF's Only!

If you are replacing the valves the seats need to be professionally cut. We offer these services a long with all engine parts required. When replacing valves it's a good time to evaluate the piston and replace if on or near the margin. The crank/rod are typically pretty solid. If you don't see any bronze-like material in the oil filter and the crank doesn't have any up/down play and is in spec laterally then I'd run with it for now.

Ken