Coil Problem?

This morning I was going on the highway starting to accelerate to about 100kms when the bike lost power. It felt like only two cylinders were firing. When you come to a stop it stalls but if you throttle it up a bit and restart it it will run but boggy. I got home and did the water test on the pipes and #2,3 are not hot at all. #1,4 are hot as hell.

I am thinking it is the coil as they look original. I am probably going to replace them but how do you check them and if I replace them how do I know what OHM they are. They are black with no markings on them.

which bike,im guessing mkII ?

1979 kz1000st or kz1000e1

shop manual lists test procedure for coils,im guessing theyre 3 ohm

The ohm is what I'm not sure of

2bskor wrote:

The ohm is what I'm not sure of

Yes,the coils should be 3 ohm. If you're replacing them you might want to go to Z1 Enterprises and look at the Dyna coils- 3 ohm will be green in colour.

You can use a multimeter set on OHMS to check the coils, just disconnect the primary(smaller wires) and put the meters probes on the primary wires terminals.

If the coils have cracks in them(a sign of age or over heating) it's time to replace them. I'd consider replacing the sparkplug leads(or High Tension cables as some people call them)too.

2bskor wrote:

This morning I was going on the highway starting to accelerate to about 100kms when the bike lost power. It felt like only two cylinders were firing. When you come to a stop it stalls but if you throttle it up a bit and restart it it will run but boggy. I got home and did the water test on the pipes and #2,3 are not hot at all. #1,4 are hot as hell.

I am thinking it is the coil as they look original. I am probably going to replace them but how do you check them and if I replace them how do I know what OHM they are. They are black with no markings on them.

2bskor wrote:

1979 kz1000st or kz1000e1

!979 KZ1000 model introduced electronic ignition with igniter, using 1.2-1.9 ohm coil primary and 12-18k ohm secondary (which would be the oem or stock coils).

If Dyna-S ignition is later fitted, the green Dyna 3 ohm coils are appropriate and the igniter is no longer needed.

There are several reasons for insufficient spark, even with a perfectly good coil.

Good Luck!

Patton said

"There are several reasons for insufficient spark, even with a perfectly good coil"

Absolutely !
dead side of points or pickup coils. bad wires, bad or loose connection. dud plug caps, dud plugs, water/rain on the electrics etc etc etc.

look for the cheap fix first

good luck

Never and I mean NEVER overlook the obvious like a broken wire !!!!! Yep a little solder and my hooptie and I are a ridin again. Thanks for all the tips !!

I want to put new coils and probably do the WG mod someday soon but there are different coils and dyna ignition etc. I know I don't have points as there is a plate with two magnet looking things attached to it inside the timing cover. Do you have to replace that or just coils do you keep your ballast resistor?

The Dyna S replaces the IC Igniter, and the pick up coils.
New ignition coils would be an upgrade and yes, the resistor would be removed using the Dyna S system.

I have the same problem on the exact same bike, it did it when i brought it out of storage this year and then once i rode for awhile it went away and worked fine untill the other day when the 2,3 went out again and i cant figure it out, when i brought it out of storage it was like the 2,3 coil needed to heat up before it would work. those cylenders are completly out at the moment and no matter how much i ride and how warmed up it is they just wont start to fire but my coils are pretty new they were put on the bike just before i bought it last fall, I have the recept from the PO to verify, dident mean to hijack your thread, I just thought it was odd the same problem on the same bike.