Small Engines (Lawn Mowers, etc.): Murray rider, hp engine, question thanks

Question
QUESTION: I recently blew the 12 1/2 hp B&S engine on my rider.  I replaced it with a 13 1/2 hp which has two more wires coming out of the motor.  My question what are these two wires for and do I need another keyed switch for my rider with more prongs on it. Everything is hooked up but the engine will still not turn over with the key.  I didn't try anything else.  Earl

ANSWER: Hi Earl
I need the model, type, and code numbers from both engines so I can help answer your question. Thanks

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QUESTION: The 12 1/2 hp on my rider is as follows model 286707, type 0115-01, code # 91051811. This is an IC Quiet engine.  The 13 1/2 hp B&S IC Gold engine I'm putting on is model 28R707, type 0140-01, code # 960729ZA. The gentleman is suppost to give me the wiring harness and keyed switch off the tractor the 13 1/2 hp came off.

Answer
The 13 1/2 hp engine is a newer engine than your old one. Two wires should originate from under the flywheel which will be your stator which charges the battery. There should also be a white wire going to the carb solenoid and a black ground wire. If you get the other wiring harness, it should have the connectors for all the wires. Hopes this helps. Electrical systems are really not my specialty.