'78 85 hp johnson - standard red plug wiring harness. When I turn the switch off, it only cuts off two of the four cylinders (same side). Usually have to choke it to turn it off after running. I'm thikig it has to be in the harness somewhere, and possibly the key switch, because it did the same thing with another motor. (140 hp OMC). Is there a point where the ground wire seperates going to each power pack or is it the same wire the whole way through? Thanks.

no, it's not the key switch.  Back on the terminal strip, there is a black/white possibly black/yellow wire coming from each power pack to the terminal strip, These are the kill wires.  The one going to the pack thats not cutting off is not making connection, possibly broken inside the terminal or right at the pack.    If one is cutting off, that means the key switch and wiring to the terminal strip is good, you problem is only with the one wire going to pack that's not cutting off.   Johnson's ground out the pack to cut the motor off, and that one pack is not getting the ground.

thanks. I'm at work now, i'll check it out in the morning. I'll reverse the packs and if that doesnt isolate the problem, time to redo the wire and connections.