Hey- just happened across this, dont know if you got it fixed but I had the same problem. Tore engine down on clutch side- there is a tensioned arm with a roller that is bolted to the engine case that keeps the shift drum in position. It is very common for the boss cast into the engine case to break, often making it necessary to replace the right side engine case- Just finished fixing one-hope this helpsI am having problems with my old three wheeler jumping out of gear. It seems to do it when i am going up a hill but after i have been riding it for an hour or so, it will do it all the freakin time. I changed out the clutch already. Any info?