Not firing and backfiring 1, 3 cylinders

I have a 1975 Z1B that is not firing and backfiring both 1, 3 cylinders ?
Spark is strong on all 4 cylinders.



The bike has new Dyna ingnition and coils.
WireGeorges wire mod.
Carbs are 29mm smoothbore.
Solid State regulator fron a later year KZ.
I was not able to check output of regulator as I was unable
To get above idle.
Bike was running fine before I put in regulator, wire mod and cleaned carbs.
Firing order is set and checked at 1,2,4,3
No changes to valve train.
I would have jump on the carbs if it just was not firing on 1,3 but backing at 1,3 ??? any helpor suggestions ????


Jim

Check the plug wires again.

It sounds like you have 1&2 cylinders coming from one coil and 3&4 from the other.

It should be 1&4 from the same coil, and 2&3 from the other.

Jeff.Saunders wrote:

Check the plug wires again.

It sounds like you have 1&2 cylinders coming from one coil and 3&4 from the other.

It should be 1&4 from the same coil, and 2&3 from the other.

YEP! Wires incorrect/reversed...

GL.

[Click on image to enhance view.]

Thanks for the suggestions, I rung out the wiring and everything is in its place.
I will pull the carbs and go over them again as a place to start.

When replacing points with Dyna-S, the points cam is also replaced with a Dyna-S rotor.

The Dyna-S rotor has a small magnet embedded that triggers each pick-up module as it passes by the module.

If the Dyna-S rotor is installed 180 degrees off, it has the same effect as if the signal wires from the Dyna-S modules are reversed and connected to the wrong ignition coils.

I would align the F mark for 1/4 with the permanent case timing mark and assure that the rotor magnet is then on the rotor's west side next to the left-hand Dyna-S module. If the magnet is then on the opposite side toward the right-hand Dyna-S module, the rotor is 180 degrees off.

Good Fortune!

Patton wrote:

[Click on image to enhance view.]

[MIG size=800] kzrider.com/media/kunena/attachments/leg...0fe3fb643c25c423.JPG [/img]

Patton you were dead on, took a second look at the coils I missed it the first time but my coil wires were reversed.
Thanks again. Bike is running great.



JIM