Craftsman is a mower name, not engine. Craftsman name has been around for 50+ years and I’ve seen almost every brand of engine used on their equipment. You may find Briggs, Tecumseh, Honda, Clinton, Subaru, etc. depending on which manufacturer built the piece of equipment. You may find the unit was built by MTD, AYP, Electrolux, Husqvarna, etc. Craftsman has never built anything, not even a decal. Sears owns the Craftsman name and only built its reputation.