i have a 02 gsxr 600, i just started learnin to scrape and the other night i hit down and the pipe caught and looped me, now my question is ever sense then it sounds like a knocking noise comin from under my airbox, everything else seems to be fine and i have no prob with the enigine i dont think, it just pisses me off b/c i cant figure out where its comin from and what it could be

 

Pull the tank and airbox and look for anything that might have come loose. If one of the hoses for the PAIR valve came loose it will sound funny.