Let's look at how the ignition coils should be wired:
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(your primary wiring may be different).
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. These ports are wired together, so it makes no difference which is used, as long as the correct coil to sparkplug configuration is followed.
The sparkplug caps should read 5K OHMS, any higher, or a reading of infinity means new caps should be ordered.
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.
If the ignition coils are original to the bike, it's past time to replace them.
Dyna makes a good replacement coil,
www.z1enterprises.com
sells a good coil, & Accel makes another good coil. I have more trust in Denso sparkplugs than NGK as I've had new NGK's fail right out of the box. A Denso W24-ESU Gapped to 0.031" should work.
