YG-1. Oh dear

[nudemetalz]

Started the strip and clean up of the YG-1 engine today.

I can see now why it was rather lacklustre in performance last time I rode it all of those years ago....

Hmmm,....top ring partially disintegrated and chomped into the head and piston crown. Time for top end rebuild.

On the plus side,..the cases come up okay

[F5 Dave]

That'll clean up with a light tickle on a lathe and say .3 off the gasket surface. Won't be perfect but small indentation in squish area aren't a real problem. You can't go too far or you'll raise the compression more than you would want.

[nudemetalz]

I spotted the 46 & 97 on the piston which means original size, hence, severe blowby on the piston and the rings breaking up from being so stuffed. Luckily, piston and rings are fairly cheap on Fleabay. Like you say, the head shouldn't be too bad.