Idle hangs on KZ 750 R1 (GPz750) 1982

[MickLC]

I think all these problems might be linked. 2 and 3 run of the same coil, so if one isn't getting spark the other probably isn't either, and they'd both be getting fouled...and if you'd adjusted the idle to cope with it running on only two cylinders then you'd get the idle speed problem you started out with. I know this because it happened early on in the Z650 project before I set the dwell on the points properly, and I'm also looking for similar (but not as bad) problems with sooty plugs on 1 and 4 at the moment.

Does your bike have points or electronic ignition? Either way I reckon you need to check the wiring again, including all the connections, because at least part of your problem sounds electrical to me.

[JudgeHawk]

at the moment it looks like your absolutely correct, Mick.

I did some checking this afternoon and amongst other things switched the ignitor coils around and checked some of the wiring. At the end the bike nearly ran perfect with almost no carbon fouling.
I probably have some wiring problems someplace around the connectors going to the ignition switch or the starter switch, because it was after wiggling these wires I got the engine running smoothly. I'm not very surprised, since I suspect nothing has been done with the wiring in 25 years.

I also suspect that the wet spark plugs are not due to fuel, but oil,
but that is another problem I can take care of after season (they are almost dry).

btw. I have electronic ignition