Hi all. So tonight I went to pick up a Ryobi chainsaw case I found online. With the $10 purchase, the gentleman threw in 3 screnches, and the 40cc Ryobi saw with 18" bar and chain! Told me the saw did not run, and his friend said it wasn't worth fixing. So, before I strip it for parts (as was my main intention), I wanted to just try saving the piston. I know it will probably not work, but just want to try it for fun and to kill some time in teh garage. I have read many topics on how to clean and save the cylinder, and a couple on the saving of pistons. My main question is what would one use to 'clean up' the slight ridges on the piston? I am assuming sandpaper, but what grits would I need. I do not yet have a picture as I just quickly removed the muffler to see and reassembled it. I will be disassembling the saw hopefully tomorrow to try to fix it up. Once I get it torn apart, I will take pictures. Thank you