Gee, wasn't that one of the motor without a quick disconnect? If I remember correctly, there was an external box that contained the starter solenoid, some fuses and connectors for the ign key. If the motor had a generator, the box also contained a voltage regulator. If so, a wiring harness is 4 or 5 wires( ground, Power, killer, start and maybe a choke wire). Sounds like trailer wire (4 conductors) might work.