I also have an old sears/ craftsman weed wacker engine i'm considering using. Its a kioritz 21.2cc engine that has idk if its points or a magneto thats in the same housing as the recoil which is in the back. It also is about a good pound less then the mcculloch engine. I can probably knock another half pound off. if anyone has any input on this engine let me know lol. thanks