John Deere L100 Wiring

[ibchewy]

I replaced my b&S 17hp engine on my John Deere L100 with a 20 hp B&S and the 20HP has three wire hook up that I need to mate to my tractor harness which has 4...The engine has a yellow that kills the engine when grounded, A white and red wire as well. The harness on the tractor had a red constant 12v and a grey that has switchable 12volts. A black which when hooked to the engine yellow kills the engine with the key. Theres a orange wire that has no power.. any thoughts?

 

[Lawnmowerman2]

Don't mean to sound ugly, but why put a 20 on a low end john deere, the orange wire and white come from the voltage reg. that plugs to the harness, the gray and black come from the coil back to the harness, the white white is ground, don't hook it to nothing.. the power in a john deere, comes from the torg, and the trans axle.. the 17hp compared to the 20, is no difference in power