Proper spark plug wires/caps for '79 KZ1000ST?

Recently, I noticed that my NGK spark plug caps were matched up with generic 7mm wires that look pretty ancient...I'm having an arcing problem in one of the caps and want some new wires as part of a restoration project.

What are the right spark plug wires for this bike and where can I find them? Would having an 8mm wire set versus a 7mm make any difference in spark potential? Suppression type wires or non-suppression? Resistor type cap or non-resistor? It would be great to find complete NGK sets (if possible). Also, any unforeseen challenges or anything else I need to know about tackling this project myself? It seems pretty straight forward. Thanks for any help.

See if Jeff Saunders at www.z1enterprises.com can get the proper caps for you.

I was able to get a hold of "Rob" at Z-1. He recommended the 7mm copper core set but was unable to tell me what to expect when removing the old wires from the ignition. He did say that depending on my ignition it could be really easy or really difficult to replace the wires. He said if the spike in the ignition comes off with the old wire it could wreck the ignition!

The new wire set consists of two black wires with spark plug caps attached on either end and you have to cut the wires in half to be able to attach the other end to the ignition. But how do you get this bare wire into the igition end? There appears to be a small plastic cap that looks like it may unscrew out of the igntion..but I don't know because I'm hesitant to start trying to remove it because I'm afraid of being unable to re-attach the new wires on the ignition, or inadvertently damaging a spike.

Has anyone replaced a wire set on one of these bikes that could walk me through how to re-attach the ignition connection? To the seasoned mechanic it must be a relatively common procedure on these older bikes. I've replaced wire sets on newer cars before, but never on an old bike like this -the ignition connection is slightly different. I don't want to make any mistakes or break anything. All I want is a nice, tight fitting wire set..Thanks for any help.

If the coils are the stock ones that came with the bike(at least on my 82 GPZ1100 B2) a spike is inside each sparkplug ignition opening. A screw off cap and a plastic compression ferrule hold the sparkplug cable secure to the coil(s.

Do your ignition leads one at a time if they are if the removable type. If not you may have to replace the coils as they age from the heat that's trapped under the tank.

If the leads are removable, carefully unscrew the plastic cap with some slip joint pliers noting where the plastic ferrule is on the lead.

Get some rubbing alcohol as a lubricant and slip the ferrule off the lead, measure your new lead for proper length and routing to avoid a short when the engine is running, place the screw on cap first on the lead followed by the ferrule.

It might be a tight fit but that's what the alcohol is for.

Push the sparkplug lead as far as possible inside the coil opening and then push the ferrule against the coil while tightening the screw on cap. Repeat for the other sparkplug leads.

7mm sparkplug leads will fit better than 8mm will. Some speed shops still sell 7mm leads, or you can probably order some off the net.

Ok, I just ordered the 7mm copper wire set from z-1. It appears I have stock coils with individual ignition spark plug leads that screw off from the ignition. What are slip-joint pliers? Are they similar to vice-grips? I guess I'll figure out what a plastic compression ferrule is when I remove one..

Some people use water pump pliers(really old tool term)to loosen the caps. But anything that will grip without crushing the caps will do. Knipex makes some adjustable pliers that will do the job nicely.

The plastic ferrule is designed to grip the sparkplug lead as the cap is tightened down. It has a taper on one side that fits a similar piece in the cap.