Well I got to tare down the PM 800 today. Not good. Anyone got a cylinder? It is not trashed, but has a small chunk of the chrome missing. Wonder if it could be re chromed. I get motorcycles re nikisiled at US Chrome but that cost 150.00 or did the last time I had one done (motorcycle). As ron said this one runs very strong and I hate to change anything. It looks like it leaned out. The seal behind the flywheel was very bad and the pulse tube from the cylinder and the carb was leaky. The biggest thing that I think caused this is the seal behind the flywheel. All the bearings look good, no play in either of them. I have been gathering the parts to refresh the saw and had plans to refresh it in a few weeks. All I was missing was the rings. That's what I get for waiting. I was having trouble with the oil pump also that could have been also causing it to be lean and I found out that the spring that held the back of the oil pump up had fallen off and could have been letting it suck a little air also. I just hope I can find a cylinder and piston that are in good shape.