If you have an electric clutch and you buy an engine without the larger charging system, you can use the alternator and regulator off of your original engine. If your fuel tank is mounted on the engine, you can use your tank and brackets or buy one with a tank. If you have a fuel pump, you can use that of your engine as well. If you buy the recoil start engine, you can use the flywheel, starter,alternator and regulator of your old engine.
