Weak attempt to start and smoke

I have an 81 KZ750 LTD I have been working on off and on for nearly a year now. When I got it, there were some shorts that were causing squirrelly things to happen. I used a schematic (that someone here on this forum helped me find) and rebuilt the wiring harness back to specs. I cleaned up many of the splices and dry rotted wires. The bike ran when I got it, but when I opened the carbs, it was only running on the two left cylindars. I found a dead bee stuck to the float on the left side, so I'm pretty sure it was not doing much for fueling the engine.

OK. So now you have more history than needed. I got the bike running again by jumping it off, but the battery was fried, so I parked the bike for about a month before I got a new battery. After charging the battery, I connected it and turned the key on. All the lights came on and everything seemed to be in order. I hit the start button and got a weak grind out of it. After about 5 or 6 times of hitting the start button, small streams of smoke started coming out of the back of the headlight.:ohmy:

I don't know if there is too much bind on the starter that is preventing it from turning over and the resistance is trying to escape by burning the weakest wire it can find or what. Obviously, by the previous statement, you can tell I'm a rookie to this wrenching business.

Any help is appreciated. If more info is needed, let me know the details required.

Thanks.

Duggie

Remove the headlight and look inside the shell. Me thinks you will find shorted and burned wiring and/or connectors.

For replacement connectors: www.easternbeaver.com , www.vintageconnections.com , www.electricalconnection.com , www.z1enterprises.com , www.vehicle-wiring-products.eu and www.autoelectricsupplies.co.uk

Any idea how to isolate where the short may be? I'll certainly pull the light again and look to see, but something is causing the short.

D7M... to isolate your short, look at the connector that connects the wiring harness to the ignition switch inside the headlight shell. It will be misshapen, melted, brown and generally a lump of molten goo. Buy a new ignition switch and get a new connector to install on the main harness. I am not sure if Z1Enterprises has the correct pin configuration but there is a VERY good chance they can get you one. You will have to clip the wires on the main harness side and carefully note wire colors. You will put new pins or receivers on these wires and insert them into the connector and then join the new ignition switch connector the the new main wire harness connector. You had a short in the connector because it has been overheating for 30 years and it finally fried. There is also a possibility that the HEADLIGHT connector is fried. this is a sub-harness where there is a red/black and red/yellow wire coming from you hi/lo beam switch go into a big black connector that is generally fried. Once they corrode a bit, the resistance goes up and they heat up and over time will just turn into a piece of melted plastic goo. Could be either that is causing your smoke.