Sudden loss of power KZ1000Police 1980

The plugs are new and I came home and checked the plugs after one of its episodes and both were black and wet with fuel from not firing. And I also had the presence of mind to check the exhuast pipe temps and they were a full 100 degrees cooler.

Stock ignition.

I heated the coil up with a hair dryer and it got really hot and it didnt seem to have an effect on it. Both coils checked out the same. I did notice when the hair dryer got close to the coil a spark jumped from the coil to the hair dryer. Kinda weird.

Both wires going into the coil are showing 12 volts. If im not mistakin only one should have 12 correct? Since this is a police model I can turn the head light off, With it off i was getting 12. 70 volts or so. With it on the voltage at the coil dropped to 9.88ish. Now could that low voltage combined with heat cuase it to fail?

Another place to look is the glass tubed fuses. They have been known to suffer internal failures and the clips can get corrosion on them. Sometimes the metal end caps get loose and the fuse acts like an on-off switch.

I believe the fuses are the AGX type(1" long) the AGC types will not fit the fuse holders as they are 1 1/4" long. Most good auto parts stores carry the AGX fuses.

Bullitt03737 wrote:

The bike is all stock. Carbs were professionally done. I know those are correct. But I can start it fine and ride it for about 25 minutes, then all the sudden its like hitting a wall. It can barely carry its own weight. I figured out it has one bad coil. Now my question is could this coil be fine while cold, but after riding the engine heats it up cuasing it to short out or what not?

That is actually the classic symptom of a bad coil: breaking down when hot. Ask me how I know.....:laugh:

Bullitt03737 wrote:

Im going to go ahead and dig this back up.


Still having the same problem. Its been parked for months and it fired right back up suprisingly. But It still has the same old problem. The 2/3 coil just stops working all together once it warms up I guess. I know for a fact the coil stops working.

The thing I have been wondering for a while now is there anything else that would effect just one of the coils once it got hot too? I would hate to think that a brand new dyna coil went bad that quickly.

Try switching the coils in the bike and see if it follows the coil. With electronic ignition, the solid state drivers go flaky sometimes.

Bullitt03737 wrote:

That sounds like an awful lot of work to swap them coils, but It has to be done.

Can you just switch the drive leads coming from the igniter to the coil to "cross test" the coils? I don't know if the Kaw design fires on every TDC like mine does or if it actually syncs to the engine based on which coil is which.

Patton wrote:

Bullitt03737 wrote:

...The 2/3 coil just stops working all together once it warms up I guess. I know for a fact the coil stops working....

Have the coil windings been ohm checked while the coil is still warm?

Good Luck!

I suspect an Ohm reading (even on a hot coil) won't show anything up because it takes a couple of hundred volts or so to get the windings to arc over through the insulation which is failing. An Ohm meter uses a couple of volts to test with.

I was thinking about doing the cross test as well, but wasnt sure if it would affect how it runs. I had this happen on my other bike (81 CSR 1000) and I replaced the stockers and it fixed it.

I just find it hard to belive that a brand new coil could fail so quickly. I THINK that this is why the coils were replaced with dynas to begin with is becuase it was cutting out on 2/3. If that is the case what should I be looking at? pickups? I will go check the fuses and holders as soon as my son goes to sleep.

Thanks for all the replys by the way!

If the coils are too low in impedance, they dissipate too much power and cook. Dyna coils are usually low impedance coils, I don't know if your coils are matched to the rest of your ignition system.

True. they are a little higher impredance than what was taken off from stock. I removed the resistor and it should be correct now.

I just checked the points, and It will flash 144ohms for a second then go back to one, I dont know whats going on with this thing. The coils were doin the same thing.