odogracing
01-23-2010, 12:48 PM
I just finished replacing piston and rings in a YFM400_Big Bear. Fires up great however once engine warms up it begins to have a slight knock. I have check valve lash and everything appears ok. Any ideas of what I can check? I have verified everything I know, valve lash, timing chain tension, I'm now at a loss. This only happens after about 5 minutes of running. HELP PLEASE!!