Well I raced a predetor and ate him up no questions asked. Then the guy I raced did a brake stand, so all the blood rushed to my dick and not my head, and I did one. Got the tires smoking and then heard a bad clunking noise. So now every time I nail the throttle the clunk noise happens. I looked at the chain and it was tight and the rear sproket is good. I took the side cover off last night and the primary drive gear is ok too. Any ideas that this might be. I dont want to jumb to the conclusion of taking the motor out and spliting the case if it could be something simple.