Cylinders 2 &3 Not firing when hot

Ok, I know this has probably been covered, but I could not find it on my search. My KZ1000 will start and run great during warm up and during first couple of miles during ride when the number 2&3 cylinders stop firing. I replaced the coil and still the same problem. What do I check next.

The KZ1000 was first introduced in 1977. As amazing as it may seem, KZ1000 models were manufactured through 2005. Without a doubt there were many changes made over those 29 years. Consequently, it would be very helpful if you would let us know which year and model you are working on since they do not all share the same ignition system. Ed

Its a 76KZ900 with a 78KZ1000 engine built to 1105, Dyna s ignition sytem with accel super coils. I bought an extra set of super coils and replaced the 2-3 coil with the new one and same problem occurred.

Thanks. It sounds to me like the Dyna ignition may have developed a problem since cylinders 2 & 3 are on the same coil and you have replaced the coil. You may want to check the see if 2 & 3 are getting any spark when the problem occurs again. Ed

I did and they aren't. When it cools a little bit she will fire again. Driving me nuts

Pic of plugs?
Steve

sparkybr74mr wrote: I did and they aren't. When it cools a little bit she will fire again. Driving me nuts

In that case I would contact Dyna and ask how to test their portion of the ignition system. Ed

I suspect it could be something fouling a plug.
Steve

Could be a pickup signal problem on the 2-3 unit
Crosscheck,, switch 2-3 pickup connector with 1-4 and the spark plugs connectors and give it a try to verify..
If 1-4 make the same problems the pickup is shot.

Checked plugs, look good. When it cools down it runs fine again until it gets hot then the 2-3 cylinders will quit firing. I going to check a couple of more things. Thanks for the help

I don't see how engine heat could possibly be causing your ignition system to fail. Other than the spark plugs, how does sufficient engine heat transfer to the other ignition parts? My guess is that the problem is operating time perhaps coupled with RPM,, not operating temperature. The primary side of the coil draws current with every spark. That current could be causing heating in the ignition. Are you using resistive spark plug caps or resistive spark plugs? If not, perhaps you should be. Are you using both resistive caps and plugs? Perhaps you shouldn't be.

sparkybr74mr wrote: Its a 76KZ900 with a 78KZ1000 engine built to 1105, Dyna s ignition sytem with accel super coils. I bought an extra set of super coils and replaced the 2-3 coil with the new one and same problem occurred.

Dyna recommends their green 3 ohm coil for the Dyna-s ignition.
What is resistance of the accel super coil?

Can the engine dying issue be quickly replicated by using a hair dryer or heat gun to apply heat onto suspected problem areas immediately after starting the engine when it's cold?

Good Fortune!