got it, thanks. The thing is, I bought this engine as used and replaced every single part, down to the bearings, except for the crank case. However, when I received it the guy scammed the hell out of me and I saw that the mounting studs to mount the engine onto the bicycle were stripped to the point the the screw was still in there, and it was impossible to get out as he used red loctite. I had to redrill a hole and it was a mm off center, since the drill bit wanted to drill in the aluminum instead of the steel. For that reason, the motor doesn't sit perfectly straight on the bike and although I have put over 800 miles on it so far, I would like to get a replacement crankcase to stay safe as I feel confident with this motor and am making longer trips. Yesterday I did a 40 mile round trip on it, with no issues.