new guy, with a 79 kz400

Hello,

I picked up a 79 z400 and started cleaning. I was able to hear it run with a jump start. I let it idle 3-4 minutes, ran up the street and back, dies and wouldn't restart, so I tried to jump it again. The old Battery has gone bad, but I'm trying to get the carbs set right before I buy a battery and get tags.
Spinning motor over, coil pops and smokes. It is an aftermarket emgo, (just has a sticker) has 2 ohms resistance across the poles. Also the bike has BR7ES plugs.

My question, could it be the wrong style coil + resistor plugs smoked the coil? I bought it this way, not running, so I don't have an original to test. It only sat not running with jumper cables applied and key on for 2 minutes tops. I was fumbling with a bare spark plug to see if it was a good spark or not. As soon as I went to hit the start button I smelled smoke.

It looks the same as the universal emgo on bikebandit, part number 2416572. The one I have does have two different length plug wires on it, but no other markings. Could stuck points points/ bad condenser have caused it? I don't want to fry another one, so any help is appreciated.

Also, if anyone has a bunch of parts for one, mine is missing a few things.

Thanks,
David

Update:
I have purchased a battery, new emgo coil and B8ES plugs, and I may buy a stock coil off ebay to have as well.

Was the battery you were jump starting from in a vehicle that was running? If so, that smoke you saw may have been your electrical system frying. Your bike will not run without a battery, but you say you plan to adjust the carbs before buying a battery. I've never worked on a KZ400, but adjusting the carbs on an engine that does not run seems like it will be difficult to do. Why not get the engine running first, even if poorly, so you can tell if your carb adjustments make things better or worse? Ed

I had a battery in the motorcycle. It just doesn't hold a charge. The jumper cables from my truck were giving the bike 12 v, just like a good battery and had plenty of juice to start the bike. once running, i disconnected them and the alternator was able to keep it running, and all the lights were functional. I was able to make sure the petcock opened and set the idle.

The previous owner attempted to get it running by unscrewing everything, even though the right side carb was gummed completely shut. I have replaced the carb holders and cleaned out all the junk, and it ran great for a few minutes.

Verify that you have a reliable spark by hooking up a strobe and see that it flashes evenly before attempting anything further.