how do tell whether the rattling noise is coming from the engine or from a loose bolt/nut or something it really only makes noise at 6k rpm bike has no fairings and a 905 cage

 

put it up on a bike stand and spin the tires.. that will eliminate the chain and sprockets.. i had the same problem and it was because my counter sprocket came loose some how tightened it up and no more problem...

check your counter sprocket.. sounds exactly like my bike.. i would make a clicking noise only in midrange under light acceleration