Originally Posted by SkiBumBrian
It is a damper for the cam chain. It goes to the front of the cam chain tunnel between the cylinder and head. DONT assemble without it. It will become obvious when you look at where it goes but if not you can probably look up placement on fiche and ronayers.com
Right you are, goes above the pin on the long cam chain slider. Tried to take a pic of it installed, but black on black and you can't see it.