The bearing on the clutch seemed to be shot so the clutch was pulled. Left hand threads. Screw or wedge a piece through the spark pug hole to stop the piston. It turned out to just be gunked up -- cleaned it and reinstalled.
Got the 45mm piston ring and put it on the original piston. Cleaned up and opened the exhaust port of the original cylinder and reinstalled, because the metal to metal fit was very good, without the gasket. This has the effect of shaving the heads about 15- 20 thousands.
Cranked it, it runs great. Let it warm up then set the carb. Idle speed to where the chain just moves then low speed mix half between max speed lean and missing from rich.
Then idle speed to where the chain doesn't move.
High speed mix would not go rich enough. had to cut the limiting tabs off.
Wow -- this is a great saw now. And Ak's are not my only problem.