Spark Plugs and Cyl order

The more I read the more I see conflicting answers. I should have done a better job marking the spark plug wire, but... I've gotten to the point in my 1975 Z1 restoration where it's time to try to start her. She turns over but backfires a lot, like the timing or the plug wires are wrong. Sitting on the seat of the Z1, I have the right coil wires going to cyl #1 & #4. The left coil wires are attached to cyl #3 & #4.

The Right hand coil has a yellow/red and a green wire going to it and the left coil has a yellow/red and a black wire going to it. I tell you this just in case i put the coils on the wrong side.

Is that correct? Thanks in advance!

It is dependent upon which side of the points you have which coil attached to. You do have it correct in that 1 and 4 are one one coil and 2 and 3 on the other.

Ignition Coil Primary And Secondary Wiring

Ignition coils on the 80’s Kz1000,Kz1100’s and Gpz1100’s are wired the same, that is as you sit on the bike, the LEFT ignition coil primary(small wires) are two wires, RED and BLACK. The secondary (or sparkplug wires) go to #1 and #4 sparkplugs.

The cylinders are numbered left to right as you sit on the seat; #1,#2,#3, and #4.

For the RIGHT ignition coil, the primary wires, again are two wires, RED and GREEN, with the secondary going to #2 and #3.

The RED wire gets it’s voltage from the run/stop switch on the right handlebar switch pod.

The BLACK and GREEN wires connect to the IC Igniter(if the bike has the Kawasaki supplied electronic ignition) it actually gives the coils their grounds to fire the sparkplugs.

Primary(small wires) side of the coils will read between 1.8 to 3.0 ohms.

Secondary(sparkplug wire ports)side of the coil will read between 10.4K to 15.6K ohms.

To stress the ignition coils, take a hair dryer, heat the coils and see if the ohm readings change from cold to hot . If they do, it’s time to buy new coils.

Keep in mind, the wiring is reversed for the 550’s 650‘s and 750‘s, that is the RIGHT coil primary will be two wires, RED and BLACK with the secondary(sparkplugs) going to #1 and #4.

The LEFT coils primary wiring would be again two wires, RED and GREEN, with the secondary(sparkplugs) going to #2 and #3.

These engines have what is known as a “Wasted Spark” that is, a sparkplug will fire during an exhaust stroke. It does no damage and many other motorcycle engines have this design.

On the points the green wire goes to the right side point (also marked "R") and the black wire goes to the point on the left (marked "L").

MFolks, I read that post earler but my bike is a 1975 Z1-B. The common wire to the coils seems to be a yellow with red striped wire. The other wire is green on the right coil and black on the left coil.

Kawasaki changed some of the coil primary wiring(not sure why) on the later bikes. On the later bikes,yellow with red stripe came from the wiring harness throught the run/stop switch and then became solid red going to both ignition coils.

And the answer is...
This is for a 75 Z1-B. The left set of points fires the plugs in cyl 1 and 4. This would be the black wire. The right set of points fires the plugs on cyl 2 and 3. this would be the dark green wire. Mystery solved! Make sure to mark your parts better than I did...

Is it running now?

No not yet. I haven't had time to redo the plug wires and coils. Not sure they are correct. It seems the short wires for cyl 2&3 somehow got on the wrong coils.

marcuch wrote:

...75 Z1-B. The left set of points fires the plugs in cyl 1 and 4. This would be the black wire. The right set of points fires the plugs on cyl 2 and 3. this would be the dark green wire....

Yessir, that's correct.

On the image below, the battery positive wire is shown in red, but may be red/yellow on the bike at hand.

Good Fortune!

Here's a link to a downloadable wiring diagram found in Filebase under KZ Information in the green ribbon toward top of screen.

Click here > kzrider.com/index.php?option=com_docman&...d&gid=262&Itemid=108

Good Fortune!

Thanks Patton. I'll re test the point gap and timing and see what happens. It has to be better than before as the plug wires weren't even close.