Coils off 78 KZ1000 work on 80 KZ550?

I'm buying new dynatech coils for my 78 KZ1000. The originals are still OK so will they work on my 1980 KZ550A ? The ones off my 550 are both cracked.

Depends on the primary resistance (which is easy to measure). The engine's with coil/points typicallyhave a little higher resistance coil like 4 Ohm ballpark. The bikes with electronic ignition were typically lower, like 2.5 Ohm ballpark. If you put a low impedance coil on a bike with points, it will fry it. But the higher resistance coil will work on either type.

My 77 KZ1000 has 5 ohm primary coils - it came with points and condenser. My '83 has stock electronic ignition and came with 3.3 ohm coils. The Dyna-S ignition system wants the 5 ohm coils. I just replaced the coils on the '83 and the consensus was "3,3 or 5 will both work."

if I understand correctly and remember right, you can use a 5 ohm coil in place of a 3.3 ohm coil, but not the other way around. Based on that, if you have a set of 5 ohm coils, they should be transferable.

Cynjut wrote: if I understand correctly and remember right, you can use a 5 ohm coil in place of a 3.3 ohm coil, but not the other way around. Based on that, if you have a set of 5 ohm coils, they should be transferable.

That's correct. It's safe to use the higher Ohm coil in either, but using the low Ohm coil with points can burn it up. Using the higher Ohm coil with electronic ign may reduce spark energy slightly but I doubt it will hurt performance.