Tore these two Stihl MS290 saws down a few days ago, washed, clean up transfer on the inside of the cylinders and ordered needed parts (pistons, seals, bearings, new non EPA carburetors and whatever else needed.) Also opened them up were they will breath better. I got the parts in yesterday and assembled this evening. Pressure/Vacuum tested, compression tested and both turned out with almost what new compression would be and will improve after a few tanks of gas. It beats buying new.