This is especially noticeable at around 60-70 mph.&nbsp\\; When&nbsp\\;I roll the throttle to pick up speed, I hear a high-pitch noise that sounds like metal is being tossed around the left side of my engine/primary.&nbsp\\; It lasts for 2-5 seconds, right in the middle of the acceleration process (it comes and then goes). The primary chain is correct tightness.&nbsp\\; What could it be?

 

Compensator........drive pulley(sometimes the lock may come off and the nut will back off).........clutch........?&nbsp\\; best start pokin' around and see