78 KZ-650-C2 only firing on #1 and # 4 cylinders ???

Just put in a new battery,carbs cleaned,dyna ignition,dyna coils,4 to 1 header. Bike started but was only running on #1 and #4 cylinders. Put in new plugs and problem didn't go away. What could the problem be ? I checked the coil wiring and it seems fine. Have silicone plug wires from coils to plugs. If you pull one plug wire off a little it will fire on the corresponding plug from that coil. Im at a loss and hope you guys can come up with a solution... Thanks Wayne

Sounds like that coil is bad. Do you have another you can swap in to double check?

You said if you pull a plug wire off you get spark, are you talking about the 2/3 wires or the 1/4 wires? If you're not getting fire on the 2/3 cylinders I'd check the coil. Is the dyna a new installation? Has it run on all 4 before now? If so, what has changed?

Nothing other then the new battery. I dont have coil's to change out with. #1 and #3 are one one coil and #2 and #4 are on the other coil. Dyna was installed last year and ran great. If I pull #1 off , I get spark to #3 and vise versa with #4 .Like I said battery is new as of the 7th of this month and fully charged.

Have you swapped the coils to see if the symptom follows the coil? If it follows the coil could be a bad coil or associated plug wires. If it does not follow the coils then could be a coil power or points problem.

Are the affected plugs showing black soot? If so,...
Have you cleaned/replaced the contacts for the coil power?
Have you done the WG Coil Re-powering Mod?

If not consider swapping the points and associated capacitor (condenser).

Best of success!

Sorry, just noticed the Dyna upgrade... forget about the points but throw away the Dyna crimp-on connector and solder the wires then protect with heat shrink tubing.

Tower_Monkey1 wrote:

Nothing other then the new battery. I dont have coil's to change out with. #1 and #3 are one one coil and #2 and #4 are on the other coil. Dyna was installed last year and ran great. If I pull #1 off , I get spark to #3 and vise versa with #4 .Like I said battery is new as of the 7th of this month and fully charged.

Hmm, it's supposed to be 1 & 4 on one coil and 2 & 3 on the other coil. Might run better if the coils were running the right cylinders

Sounds to me like he has the wires right...
See if there is any arcing.

As steell says, one coil fires outside plugs #1/4. And the other coil fires inside plugs #2/3.

Plugs are numbered starting on the left (gear shift) side of the engine.

Good Luck!

Went thru the same thing yesterday, 2-3 coil checked good on primary & secondary side but bike wouldnt run on it. Swapped one from my other Z1 and it ran perfectly. Still dont understand it

Oppsssss my bad, it is #1 and #4, #2 and #3. Maybe the #2 and #3 coil is the problem.. Hmmm I guess I'll start with taking the wiring apart and go from there...

If not already done, would remove plugs and inspect spark on each plug as engine is cranked over with ignition switch on.

Seeing spark on the removed plug is a fair indication that it's also sparking when installed.

Good Luck!

Today I checked the coil for #2 and #3 cylinders with a test light and got power at both terminals. I did the same test on coil for #1 and #4 and only got power at top terminal. I pulled the coil for #2 and #3 cylinders and did a check with a Ohm meter and got 4.1 Ohm's between primary leads. It should be 2.9 - 3.2 Ohm's. I checked the secondary and got 14.8 K . It should be 13.5 - 14.5 K . I then tested the coil for #1 and #4 and got same reading on Ohm meter. Put the #1 and #4 coil back in place of #2 and #3 coil and vise versa with other coil. The problem DIDN'T follow the coil swap. I then pulled the point cover and checked the Dyna ignition and found that if I wiggle the pickup for #2-#3 coil I can get it to work. Hmmm it feels as thought that pickup box has gotten hot and the cover is very loose. I will have to get with Z-1 enterprise and see if I can get one new Dyna ignition pickup for the #2 - #3 coil side. Dang it !!!

Thanks for all the help guys... Wayne