RM125 High compression base gasket causing serious problems.

Long story short I bought a Facebook marketplace 2000 RM125 and freshened it up. Motor ran very well when I got it, but decided to pull top end apart and inspect anyways. Piston was clean, ring was good, cylinder walls spotless, and zero up/down crank play.

Reassembled with a high comp base gasket and new ring. It makes a little more power now, I’d say it’s a bit snappier. But the engine sounds like it might have piston slap, it’s a little noisy, like a bit of a tick all the time. I’ve also had to jet richer on all circuits multiple times to get rid of some nasty mid/high rpm detonation. 

I’m running c12/93 pump cut in half with klotz at 36:1. Today I took the expansion chamber off to clean out the inside. I take a look at the piston from the front, it now has some scoring marks, the top half of the piston is black, and I can see some scoring on the cyl walls with a flashlight. About 2 hours run time since it was apart. What the hell is going on. I’d like to finish off the season without this motor imploding. Bike runs well and makes power but like I said, it’s noisy.