I have an old 11 hp Craftsman lawn tractor with a launched motor, and I have on hand a newer 15.5 hp motor. I have already swapped motors and all belts and guides line up fine. Can I use the older wiring harness or do I have to use the one for the newer motor? A simple wiring diagram of the newer 15.5 would help a great deal. Thank you so much.

Tom Jewell, June 2009

There's no real reason why you can't use the original wiring harness, as both engines will probably have magneto ignition....however, you'll need to identify the various wires that come from the engine. One will be an ignition cut out, one or maybe more will handle the battery charging system and there could be a wire that goes to the carburettor float solenoid, if the new motor has one.

John, June 2009