Battery connected backwards ‘81 kz750 LTD

I recently bought a kz750 Ltd.
Problem is, the guy I bought it from connected the battery backwards. Result of that was a wire caught fire and I was wondering what problems could result from connecting your battery backwards on a kz750 and what should I do to problem solve this? Any help would be great appreciated!

There's a warning in the 81 KZ650 manual that says the zener diode in the voltage regulator can get burned out. I don't know if the igniter or any other component would be affected. some other parts with circuitry that might be affected include the turn signal operating switch, reserve lighting device & fuel check switch.

If the reg-rec is shot, you can use one from a Ninja 250/500 or Vulcan 500 up to at least about 2009 (credit to loudhvx). These are virtually identical to the stock unit. on some of them the connector is reversed, so you'd have to change out the terminal pins.

I appreciate the help! I checked some wiring today and it looks like my reg did get burnt from the mishap. I will have to follow the wires a bit more to see what other components were hurt by this.

Once again thank you! This is my first bike and I’m really excited to get this bike back on the road.

Maybe you have it already, but there's a 750-4 pdf FSM available.

I’ve talked with another kz750 owner over Instagram and he had emailed me the PDF for this bike. I appreciate the help though!