misfires again

Ok, I have an 82 kz1000 ltd. 20k on the odometer, new plugs, new plug caps, carbs cleaned thoroughly, several times, carb floats set, runs beautifully cold. Once it warms up it drops off cylinders 1&4. Barely idles, hardly accelerates. After it cools down, it runs fine again. I checked voltage at the coils, checked resistance at the pickups both hot and cold, did the gmt hei igniter mod, nothing helped, swapped out to a supposedly good used coil, tried another set of plug wires. The spark on 1&4 is very weak once warm. I am leaving for a 1400 mile road trip in 6 days, I NEED HELP. PLEASE. I had the wired George coil relay mod, but it did not help, and the relay was sticking so I took it off, that didn't help either way. I am going to try swapping coils side to side tomorrow, to see if it changes to 2&3, or not, though I believe it won't.

On mine when I had a miss, it was the plug wire. You put on new caps, but did you replace the wires?
Maybe to help pin it down, take a couple of small 12v bulbs and wire them across the primary connections at the coils, 1 to each coil. That way when the Pick-up coils, and ignitor is functioning correctly, you will see equal flashing on both of these test light bulbs. Wire up to the Handle bars so you can see them. If it is missing but both lights are flashing equally and the same as before the miss, then it is in the secondary ignition.

hiroshima1320 wrote: Ok, I have an 82 kz1000 ltd. 20k on the odometer, new plugs, new plug caps, carbs cleaned thoroughly, several times, carb floats set, runs beautifully cold. Once it warms up it drops off cylinders 1&4. Barely idles, hardly accelerates. After it cools down, it runs fine again.

classic symptoms: bad coil

That bulb idea is great. I'm gonna have to try that one tonight.

bountyhunter wrote:

hiroshima1320 wrote: Ok, I have an 82 kz1000 ltd. 20k on the odometer, new plugs, new plug caps, carbs cleaned thoroughly, several times, carb floats set, runs beautifully cold. Once it warms up it drops off cylinders 1&4. Barely idles, hardly accelerates. After it cools down, it runs fine again.

classic symptoms: bad coil

That was my original thought, but I kinda ruled it out, but I think maybe the coil I used was bad too.

hiroshima1320 wrote:

bountyhunter wrote:

hiroshima1320 wrote: Ok, I have an 82 kz1000 ltd. 20k on the odometer, new plugs, new plug caps, carbs cleaned thoroughly, several times, carb floats set, runs beautifully cold. Once it warms up it drops off cylinders 1&4. Barely idles, hardly accelerates. After it cools down, it runs fine again.

classic symptoms: bad coil

That was my original thought, but I kinda ruled it out, but I think maybe the coil I used was bad too.

Yeah, when my original coil failed I bought a "good used one" that failed almost immediately.

Ok, I swapped coils side to side, and pit lights on the negative and positive connections for the coils and with the bulbs in the bike wouldn't start.... I took the bulbs out and the bike started. I put the right bulb in (for 2&3) and it lit up and continued to rub well. I put the left bulb in (for 1&4) and the bike wanted to stall. I ran the bike until it started to miss. Pulled the 1&4 plug wires and no change in engine running... I put the bulbs back in and they both lit up. SPARK PLUG WIRES! Can I nip off a half inch on either end or should I just get new ones?

New ones can be had from the auto parts store or the bike shop by the foot, Less than $1 a foot.

Ok, I got some plug wires from my local kawasaki mechanic and kz guru. Put them on and same problem. I now have very strong spark, but after riding 10 minutes give or take, I drop 1&4. Barely make it home. Occasionally it surges violently and other times less violently, but overall, it runs horrible after that first 10 min of good running. The petcock seems to be flowing very well, but the service fuel level is extremely low on outside carbs.... I put a new fuel filter on and same results...

Have you checked the screens above the float needle and seat? #14043 in the fiche.

hiroshima1320 wrote: ...after riding 10 minutes give or take, I drop 1&4... runs horrible after that first 10 min of good running....

May result from insufficient valve clearances.

Good Fortune!

I did a hot and cold compression check, so that pretty much rules out any valve issues. I took the carbs off and the fuel cross over tubes were full of gunk. Cleaned out my tank again, I'll let y'all know if it does any good.