After 10 years and at least 10 000 kms of rippin on my 2000 YZ426F with nothing but just preventative Maintenance, I munched something in the transmission. It is stuck in gear and will not roll. Took out the clutch plates, and I don't see anything unusual. Have not pulled clutch basket out yet and I read on the internet that some of these bikes had trouble with shift forks. I was wondering, if it were the output shaft, gears or shift forks, can the gears be pulled out with the engine in the bike? and does the whole engine have to be disassembled? (head, cyclinder) Anybody have the same experience? I now know why my chain was jumping (slapping) so violently. NOT just regular Chain Slap!