My Bike Has Been Making A Lot Of Noise Lately

Rocker arms

What you see in this picture is the chewed up rocker arm of a 500cc single. A few months ago this bike came in with that really bad top end noise and it turned out that it didn't have ANY oil in it. It ran for a little while longer after refilling it, but it eventually died.
When we took the bike apart, we discovered where that very awfully loud noise was coming from: one of the rocker arms had worn paper thin, so the clearance between the rocker arm and the valve got rapidly bigger, making all that racket and the piston was worn out, too.
The damaged rocker was on the exhaust side. The engine would suck in fuel but because there was a big gap between the rocker and the valve, it wouldn't really open, not releasing the burnt fuel, causing it to not run anymore. The piston got damaged also when it was run low on oil, so it's getting a bigger Wiseco piston now!
So there is an upside: Our customer took the opportunity to make the engine faster and better and it'll run like a bat out of hell once we're done with it!
He's also doing some custom work to it, will post pictures when done! It should turn out pretty nice.