I picked up a couple of free engines at one of my stops. Got them home and decided to strip all un-needed pars to discard. The one was a Sears. I thought it was a 31cc Ryobi...but it said 25cc. Also the air volume and speed was printed on a sticker. Quite high figures. I had a heck of a time digging the engine out of all that junk plastic. I took the exhaust off...to my surprize it looked like new inside. Also the ports was of good size. It sure was a oil mess inside case. Then I noticed the cylinder was loose. It looked like it leaked from brand new and got more loose as time went on. I tightened the 2 cylinder hex bolts. Primed the carb and it started and ran on 2nd pull!!! Crome bore and 2 rings. It sure reved up quick too. The no 2 engine was a Ryobi with a nice looking piston excep for one area. I believe it has a stuck ring. I will look up the specks on the Sears later...it has a model no. Let us know about your finds! Capt,n