Hello, I'am new to this forum and by reading some of the questions and answers here I know I could possibly find some help. I recently bought a 87 XR600 in good condition. The guy I bought it from said the top end was a little noisey. The bike starts good and run pretty strong. I checked the valve clearence and they are right on according to my Honda manual. What else could be making this noise? It doesnt sound like a piston, I had it at my local shop and they did'nt help much. They thought it was coming from the intake side. Other than this noise the bike runs good. Any ideas? Thanks!