You need a new cam chain.I'm rebuilding my rearend. New CV Shafts (more to come on this) bearings in hubs and final drive. While its all apart, new rear brake pads.
I think a timing chain is going to be in the mix pretty soon too.
This motor is fresh though. Maybe 50-60 hours on it. I've rode less than 10 times here in Texas, and one trip to Tennessee.You need a new cam chain.
I would also recommend removing the ignition cover and checking for debris inside the flywheel. May sound wierd but you be surprised how much metal is in there. You'll find find lots of grey sludge and a few flakes of metal. This will tell you how good or bad the motor is doing. Bigger the chunks, the more the need for a rebuild.