Reply to thread

Message: [QUOTE="98yz400, post: 1113812, member: 73215"] my brother has the same bike i do, yz 400f, and last season he fell and sand went into his exhaust and slid all the way into the cylinder. so we replaced the rings and gaskets and cleaned everything out. then after we got it back together and started it and test rode it, we eventually came to the cunclusion he needed some new valves. now its all back together and he doesnt have the insane compression he had before, he can kick it like a 2 stroke without the compression release. it idles fine but it bogs in low RPM's under aceleration. we're baffled. [/QUOTE]