To hone or not to hone...

[afrausini]

You said that this was a MS391 yet you post photos of an 1125 cylinder from an 034, 036, MS360. So what is it you actually have?

Your next project is to figure out why it scored in the first place before you do it again.

oh my.. it was 034av… i was working on a 391 and mixed them up

 

[afrausini]

OP was it scored on both sides of the piston or one?

both

 

[lone wolf]

both

That points towards straight gas being the culprit usually.

http://www.madsens1.com/saw_piston_fail.htm

 

[cookies]

Clean the aluminum from the oem cylinder and stuff a new oem piston back in then pressure/vac test it, the value of a all oem saw vs aftermarket is easily double. I would not make a name for myself selling saws without disclosing aftermarket parts contained/listed there in.
If you buy aftermarket parts you better have the tools to check cylinder bore out of round and piston size. Yea you'll get lucky a few times without doing so but it will bite you eventually. If your not prepared to spend 10 hours tearing one down to clean/rebuild it you won't go very far buying old saws to make money, You will waste more time doing things over and over when a cleaning and full tear down from the get go on scored cylinders/pistons would have saved time/frustration and increase the value because its clean. Vac/pressure testing also needs to be employed.

 

[AndrewAmerico]

OP was it scored on both sides of the piston or one?

 

[AndrewAmerico]

That points towards straight gas being the culprit usually.

http://www.madsens1.com/saw_piston_fail.htm

Ah....thanks so much. Love the education! I'll still pressure test to make sure all the seals are good and check the manifold boot.(if that's what you call it)