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Hi guys, I hope someone can help with my confusion. I have a 1978 KZ1000 and I need to replace my ignition coils. I am confused because the existing coils are as follows:
as sitting on the bike
Left coil has plug wires going to Cyinders 1,2
Right coil has plug wires going to Cylinders 3,4

I am confused because the manual has the plug wires crossing over the engine. When i buy and replace the coils, should I replace as installed, or follow the manual? Mind the bike was running just fine until I slowly started losing spark towards the end of last summer. As of now cylinders 3,4 have very weak spark and 1,2 no spark at all.  

With the coils hooked up to the spark plugs as you describe, the engine could only run on two cylinders. I would try hooking them up correctly and see what happens.

I would normally agree with you based on what the manual says, but Its been that way as long as Ive owned the bike. It ran all last summer with no issues until early fall when it slowly started losing spark . I will take a picture tomorrow afternoon to cross reference. It just doesnt make sense to me. 

I'm surprised your engine runs!

The correct hook-up is for the left coil to power 1 & 4 and the right one to power 2 & 3.  For every half turn of the crank, each coil fires for both cylinders at the same time, but one cylinder is on the intake stroke and the other is on the exhaust stroke, so there is no detonation on that one.  

You may not need new coils.  Just hook them up correctly and see how it goes.

If you have the fuel tank off, which I would assume you do, take a picture looking down at the top of the engine so we can see the coils and how the spark plugs wires run from each one and to the plugs.  As has been stated it would be almost impossible for the engine to run correctly with the wires connected as you describe.  Interesting to say the least.

Rick H.

Also need pictures of the wires and colors coming from the points/pickups to make sure the secondary wires are connected to the correct coil. 

Well it was my mistake to speak before I took a better look. The plug wires are ran as should be. I busted out the multimeter and did the old spark plug to ground test. I only have spark on 1 out of 4 cylinders. Ordered new coils and will test again when they come in. I verified switch voltage to the coils and ran continuity from the points to the coils. Anything else I should look for? And thanks for all your responses

What resistance did you measure on your coils?  They may still be fine.  You may have plug wire problems.

As my father bought the bike brand new in 78 and knowing what work has been done to it, the coils and wires are original to the bike. I've owned it for a little over a year now. I've already ordered new coils, that come with new plug wires. I forgot to read through the coils themselves with my meter though. 

I'd swap the coils to see if the problem stays with the coils or stays with cylinders.
You could also have a bad condensor or bad wire.

I would also take a very good look at the points. If the rubbing blocks have worn down too far, the points may not be opening enough to reliably break the circuit, thereby preventing the coils from firing as they should.

I agree with everything here. Just wanted to suggest you pop by the New Members forum and introduce yourself and your bike. We love pics!