TOPIC:

I just got a 1980 KZ650 and 1 of the cylinders are not working. It is the 2nd or 3rd one I can make sure later. The spark plug is not getting any electricity. I believe it is the coil.

I was just wondering if anyone else has any ideas about this? Also anyone know where I can get a Coil for a good price. Also does anyone know if there are other coils from other bikes that would work?

Thanks alot.

Welcome to KZr takuma.

If the coil was bad, it wouldn't send power through to the other spark plug.

First try replacing the spark plug with another one (new plugs have been known to be defective at times).
If no spark still, then unscrew that spark plug cap and place the end of the plug wire against the cylinder as you hit the starter button (carefully keeping your hand far enough away from the end of it ).
If you get spark now, then either the plug cap is faulty, or simply wasn't making contact with the wires.
If you trim back about 1/8" off of the end of the plug wire, you can "renew" the spot where the plug caps threaded stud screws into it.
If still no spark though, then check to see if that plug wires is damaged and causing your prob.

Welcome to KZRider!
The 650 has two coils, and one fires cylinder 1&4, the other fires 2&3. If one plug fires, either 2 or 3, then the coil is probably good. You may have a bad wire/cap or a bad plug.

Remove plugs 2&3, and see which spark plug is firing. Remember to keep them laying on the head, or touching the head somehow..

Then switch the plugs to see which one fires. If the same wire keeps firing then you'll know the plugs are good and the dead wire needs help.

It is not uncommon for plug wires to corrode on the end that fits in the plug cap. You can gently twist and pull off the plug cap and clip off 1/4" of a corroded plug wire and often get a good spark again. If this works then all is good.

If clipping the wire does not work then remove and swap caps. If the dead wire works after the swap and the other wire doesn't then you narrowed it down to the cap, and can buy a new one.

Thanks alot guys. I'll check that stuff out tomorrow hopefully.

However I assumed those weren't the problem because I checked each wire with a timing light gun. The 3 working ones made it flash but the nonworking one didn't do anything.

I checked the wires and they were fine. I was wondering if anyone knew if this coil would work on my KZ650
cgi.ebay.com/ebaymotors/USED-Ignition-Co...QQrdZ1QQcmdZViewItem

Or do you know any other inexpensive Coils I can replace it with.

Thanks alot.

They may work, not sure tho..Lou would know, send "loudhvx" a PM, he knows 550's and ignition electrics better than most.