Warning 520 EXC owners! Do adjust chain exactly as manual. Mine was probably a little too tight, and i broke a link on the chain in half. Winter riding cold, and miserable out. Chain snapped, broke magneto cover, clutch master cylinder, and chain guard! Anybody hear of this happening before? Anybody know a price of the master cylinder for the clutch. I am mad as the threaded parts going into the case will have to be welded and re threaded. Never seen damage like this before, never seen a 520 o ring chain snap like that before. WOW!!!!!!!!!!!! Anybody know of a real chain protector?