See if this helps.
What make and model of engine is this?
Engine make: Kolher Magnum
Model is M20 49506 XXXXXXXXXX /p>
See attached link. Enter m20 in the model number box. On the next page scroll down and look to the right. It will say service. Click on that and you can download the service manual. Go to the electrical system and it will give you a basic kohler wiring diagram.