Time to replace the coil packs?

I'll start off with the basics... 1981 KZ1000, rebuilt with parts from a couple different bikes, everything is pretty much original.  The coils were probably weak when I first put it all together, I've always had that gas smell from it running, and it never had a whole lot of power (which is why I'm leaning towards coils here).

Trying to get it going this week for the season, but it's just not happy.  Cranking it so much that it's pumping gas onto the ground so I presume flooding out the cylinders.  It does eventually start but there's very little throttle response.  Cleaned the plugs twice.  Today when I cleaned them, inside right cylinder plug is completely covered in carbon.  If I can get it going long enough to ride up and down the street, it takes a lot to keep it running, and there's backfiring on the right side.  The left side seems better, but still not putting out a lot of heat to suggest that it's really running well.

Another thing today, after cleaning the plugs and getting it to start again...  I can barely keep it running, but then something catches and it jumps up to 3000rpm.  It'll run there for a couple minutes, then choke itself out and die again.

So from my knowledge, this all points to little or no spark.  If anyone has other ideas, let me know?  (Erg it just occurred to me that I should have pulled the cap to check the points.)

And if the coils are indeed the problem, then the question becomes what should I replace it with?  I'm hoping to keep it simple, something that is a straight OEM replacement that can drop right in without having to do any rewiring.  Modern replacements are fine but this is just a street bike so I don't need anything fancy.  If there's something I can snag off Amazon then maybe I can try doing the swap next weekend.

Coils get a lot of blame, but rarely fail.  You can measure their resistance.  If you really want to do a solid, replace the leads with 7mm copper core spark plug lead wire, and measure the cap resistance, or just replace the caps with new 5k ohm caps.  

Regarding the running issues, it's hard to say.  Likely carbs.

When checking coil resistance don't forget to check between primary and secondary windings (should be infinite) and also between both windings and the mounting post (should also be infinite)

Stinks of fuel, black carboned plugs, it obviously running way too rich.
you only need choke to get it warm, if you leave it running on choke until it dies then your plugs will have carboned up to the extent they'll no longer spark. If they are ngk plugs and get to that stage they are almost impossible to get back in decent shape regardless of how much cleaning you do.
ALL your description points to overly rich mixture and carb tunning and nothing to do with weak coils.
if you truly believe you have weak coils, or low voltage to the coils, test them as per fsm and fit wired george mod to facilitate full battery voltage to the coils.

Shdwdrgn wrote:

  Today when I cleaned them, inside right cylinder plug is completely covered in carbon.  

Swap the leads to the #2 and #3 plug. Or switch the coils around. See if it is the same spark plug that gets carbon fouled.
Run the bike in a dark place. look for electrical arcing from the coils and plug wires.
You can also make a simple spark distance tester with a block of wood and solid copper wires.
In my experience, I have never found a weak coil. They are either good or bad.
Carbs are more likely the problem.

Wow ok, so it sounds like I'll be pulling the carbs.  Maybe a stuck float or something?  When I rebuilt the bike I also rebuilt the carbs, so new floats, gaskets, valves, and of course spending the time to adjust the float heights... it would suck if anything actually went bad already.

So just to clarify... I originally pulled the bike out Friday afternoon.  I was able to get it started with a lot of effort (which was surprising because last year I didn't even have to charge the battery, it just fired right up).  I had to jump-start it because the battery was nearly dead so that's when I was trying to ride it up and down the street, but that's also when I was cranking it so much that fuel came out onto the ground.  Then Saturday I thought to clean the plugs -- they weren't terrible, but they were all wet.  So when I got back to it again yesterday I still had to use the jumper cables.  There was no flooding onto the street this time, but even when I got it to start it would barely run.  So I pulled the spark plugs again, that's when #3 was carboned up.

Regarding the choke... I have never been able to start it without being choked.  Most of the time even when it's hot it still won't start without some choke.  Yesterday I tried starting in all three positions to control the flooding, but it still would only try to start when fully choked but with the throttle cracked a little -- which is different than previous years where it needed to be fully choked and the throttle fully closed.

So other than checking float height and the valves, anything else I should pay special attention to when I have the carbs apart?  I am assuming there is going to be issues across all four, otherwise the bike should be able to run on only three cylinders (albeit rough).

Before disassembling the carbs, do a clear tube fuel level check on them.The problem may be only that one carb is flooding.
When finished working on carbs, I always do a bench test clear tube fuel level check, using a fuel bottle. It catches problems before mounting carbs back on the bike.

Sheesh it's been so many years ago that I completely forgot about that method.  I'm pretty sure I used some extra aquarium tubing to calibrate them to begin with, and we still have plenty of that kicking around.

Is the engine oil level really high or does it smell like gasoline? Could be float valves not sealing. The clear tube method will show really high fuel levels if the float valves not sealing is leaking.

Also, there are no points to check. The 1981 1000s have electronic ignition.