I hope someone out there can help me. I have an 03 foreman 450 ES and I just replaced the crank and the guy that is doing the machine work has had several months. I got it back after he changed the crank and it ran about 30 minutes before making a funny sound and shutting off on its own. When I took it back to the guy he said that the key on the crankshaft sheared off and now he claims that it keeps shearing it off and I'm not sure what could cause it and I don't think he has any idea either. I hope that someone can help me. Thanks in advance.