I bought this engine a few days back, I didnt give a whole lot for it. The man I bought it from thinks its a Sachs 3.7 or a 60cc it weighes 6lbs and 3oz. Ive looked inside of the piston and it looks brand new and the outside is very clean aswell, this engine doesnt have much run time on it from the looks of it, but who knows? Please look at it and tell me what you think it is.