Thank you for the wealth of knowledge and information on this forum. I have been in the tech section and through a couple threads to try and diagnose the issue I am having. I believe my machine is a 1978 390 OR or a 390 AMX. It is in incredible condition. The issue is I believe in the clutch drum or somewhere behind it. When kicking over the kick starter, the crank will not turn over. The brake lever on the right side of the case is working properly. I opened up the side cover and found that the clutch drum spins freely as I spin it. Don't completely understand why. Is this suppose to be the case? If so, I am trying to understand how the crank can turn. Piston is free.