KZ 1000 P1 ignition coils

Can any one tell me the difference between the left and right ignition coils used on the KZ 1000 P1
(Cyl 1&4) 21121-1038
(Cyl 2&3) 21121-1039 or 21121-1310

The coils should be identical but the sparkplug wires may be different lengths and the ignition wires may be different colours.

Thanks for the Info there is quite a price difference between the two part numbers the highest price coil has the shortest leads

What year is the bike? Does the circuit have a ballast resistor?

A KZ1000-P1 should be an 82 model. I bet the coils are identical except for the spark plug wires. He can probably use the coils from any KZ1000P Police, sold in the USA until 2005. Alternatively, Accel or Dyna should have something as well.

The LH & RH coils on my 81 KZ650-CSR have different Kawasaki part numbers, but they are identical, having the same numbers & markings on them and they are embossed with Tec. I assume Tec is a Japanese electro mfg. The spark plug wires are removable by unscrewing the ribbed compression boots. My bike has the stock electronic ignition, but I'm running the green Dyna 3.0 ohm coils.
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My bike is a 82 KZ 1000 P1 It was running crappy after a long run . Runs rough , pops back through Carb # 2 it runs good at highway speed and when cold. I did compression test all cylinders were 140-145 PSI , I adj valves ,balanced carbs and replaced coils with a new set from caltric both coils were same part# Bike would not even start until I put the Original coils back on . I’m at square one again pops back through Carb 2 when hot #2 ex pipe is cooler than the others and plug is damp all plugs are black and sooty. Any ideas?

It’s a 1982 no ballets resistor

If your bike runs then the coils are probably fine. You should check the voltage at the coils to see if you're getting 12 volts. If not then you can do the relay addition shown on wiredgeorge's site.

Do you have points or electronic ignition? If points then you should check to ensure proper settings.

Popping and backfiring when revs are dropping is normal. If it occurs when riding at a steady speed then you have a fuel problem. Damp or sooty plugs suggests you are running rich. If you are fuel rich at low rpms then you should adjust your air screws if you have them, or your pilot fuel screws if you have them. Running rich at highway speeds suggests an adjustment of the jet needles. At very high speeds it would likely indicate your main jets are too big.

If your air intake and exhaust systems are stock then you should check your carbs to ensure they have stock jets and settings.

Thanks I will check voltage at coils today

The bike is all stock it does not have points

All stock is good...it means you can return all adjustments to stock and hopefully have it running well.

Another thought....Try removing your air filter. Does the bike run better? If so it indicates you are running too rich a fuel mixture under normal operation. Check/clean or replace the filter with a new one.

If not already done, would perform clear tube test to assure fuel level is within specs, because a too high fuel level can produce the reported symptoms in an otherwise perfect carb.

Good Fortune!