TOPIC:

Well, I tested the IC Igniter per factory manual, and the results were rather discouraging. The test is done on the pickup coil side and on the harness side.

The pickup coil side was right on:
Blue & Red to Black/Yellow is 30 ohm, spec is 25-45 ohm
Black/Yellow to Blue, Red is 34 ohm, spec is 20-40 ohm

The harness side is an entirely different story:
Black/Yellow to Black, Green spec is 0, tested at 0
Black, Green to Black/Yellow spec is 200-500 ohm, tested at 1000 ohm
Red to Black/Yellow spec is 200-600 ohm, tested at850 ohm
Black/Yellow to Red spec is 300-700 ohm, tested at 900 ohm

I repeated the test three times to verify I wasn't setting the multitester wrong, or mixed wire codes. But, alas, the test results remained.

The primary and secondary wiring on both coils came in at a consistent 2.0/12.0 ohm numerous times, the pickup coils tested at nominal, and it appears reg/rec has continuity and tested fine.

So I guess my problem with misfiring is caused by a failing IC Igniter, which is the one part that cost the most...

Oh, well, it is what it is, I guess. Getting a Dyna S ignition and coils won't help this one, I still need an igniter. Anyone have any suggestions or insight?

... but the IC igniter is the cheapest one to make:
www.geocities.com/loudgpz/GPZgmHEImod.html

Do you know which cylinders are misfiring? If so, you can do tests to verify, for sure, it is the igniter and not the pickups by swapping some wires around. The ohm tests are not really accurate tests. Semiconductors give widely varying resistance values based on tolerances and the actual meter itself.

I put the details in your other thread on this problem:
Previous thread


Also, the dyna-s IS an igniter mounted to the same plate as its pickup. Dyna-S, plus coils, would be replacing the entire ignition system except for the plugs (you already replaced the wires).

Post edited by: loudhvx, at: 2007/09/07 21:01

loudhvx, I didn't realize that the Dyna S ignition kit also replaced the old igniter. No, I do not know which cylinder is missing, I get easily lost in the electrical/electronic world.

What you're saying makes a lot of sense - the factory manual sorta described the tests as real definite: "if you don't get these results, replace so and so"... And the multitester I have is a Radioshack cheapo I've had for years, so if you add that to an electrically challenged dufus, and old components, and somewhat inonclusive test methods, well, you get to be like me: duh, uh, well, how, uh, can it, ah...

I'll go back and re-read your guidance in the other thread, I really want to figure this one out before I start spending money on parts there's nothing wrong with.

Thanks for taking time to respond (the 2nd time, )

Walter

Okay, I know I'll look like a complete moron here, but I want my bike back and I have long since given up on looking cool...

It seems to me that I really have to know which cylinder(s) is missing in order to trouble-shoot. I know the engine is missing, I can feel it faultering and jerking/clunking, but I don't have a clue how to narrow the problem down to 1&4 or 2&3, let alone a specific cylinder.

All the pipes get equally hot, all the plugs looked identical on the plug chop, both coils read the same on primary and secondary. Do I need to buy a timing light, and would that even help?

I think I understand how to chase the problem, but I need to know where the problem originates, right? Jeez, I'm lost here, guys.

Post edited by: Norseman, at: 2007/09/07 21:47

Are you still using the original spark plug caps on the new wires? If so, did you check the resistance of the caps?

From what little info you have provided, it appears that the bike is misfiring only under acceleration, if that's true, then it is most likely caused by a weak spark.

The only things I can think of that would cause a weak spark are :

(1) Bad (high resistance) igniter ground
(2) Bad coils (you don't mention the secondary resistance).
(3) Bad plug wires (but you have replaced those)
(4) Bad plug caps (high resistance and a real common problem)
(5) Bad plug(s)
(6) Reduced voltage to the coils (less than 12 volts)

It takes more energy to fire a plug under higher pressure, and when you open the throttle you are increasing cylinder pressure.

This may have been asked in some previous thread but have you done the WG Coil Repowering Mod? Given no other charging faults, this would eliminate the posibility of low voltage to the coil(s) at a very low cost.

Best of success!

If the problem is too intermittent to study while the bike is sitting in neutral, then, in the end, it is probably faster to swap in new parts. The problem is, this is very expensive way to troubleshoot.

If you have an inductive timing light, that would help a lot as long as the problem occurs while the bike is sitting in neutral. A timing light will tell you which plugs are not firing. A timing light is also a good investment, so if you don't have one, and plan on tinkering with bikes, it's a good idea to have one. If you get one with a timing dial on it, tape the dial to zero degrees.

Also, as Bill mentioned, it probably would be a good idea to make sure you have at least 14v on the coils while you are trying to rev the bike. That way we know the power to the coils is good and the charging system is good. If the charging system is good, but the voltage is low at the coils, you may want to consider the WG relay mod, (or fix whatever is causing the voltage to drop).

Thanks so much, steell, bill and loudhvx, I do appreciate your help.

I did get new caps as they were part of the new Dyna wires. However, I have not checked igniter ground, so that may be the cause - I will trace and check, though.

I can't believe I forgot to include the coil secondary test result:blush:
Primary is 2.0 ohm on both coils
Secondary is 12.0 ohm on both coils

Yep, I have done the WG Coil Repowering mod recently, but it didn't affect or reduce the misfiring.

In terms of bad plugs, I put new plugs on when I bought the bike, but that does by no means guarantee all the plugs are good, and I did have one incident where the engine overheated (I took PO's word for "just changed oil" and turns out he had parked the bike for two months after oil change with manual petcock on open, and there was almost a quart of gas in the oil, thinning it out to water-viscosity, shame on me for not verifying). I will buy four new plugs today and test.

Finally, I am concerned with the battery/charging after doing the charging test yesterday by measuring voltage across terminals. I did have to add distilled water prior to test as cells 1 & 2 were about an inch below the minimum line, and charged on my battery tender overnight. But then when I ran the test, at idle the multitester needle went straight to 15 volts, and stay there when I reved to 4,000 rpm - it didn't move. I did the test three times with same result. I don't know if this indicates a bad battery, or a bad reg/rec, or both.

Thanks again for taking time to help me, you guys are really great!

Post edited by: Norseman, at: 2007/09/08 13:38

Looks like we posted at the same time, above. 15v is a little high. This could indicate a little voltage loss somewhere in the bike which tricks the regulator into putting out too much voltage into the battery. However, this shouldn't cause misfiring unless the voltage jumps up to 20v or so.

I'd recommend a timing light, as I mentioned above.

Just an observation...

You probably meant "Secondary is 12.0 K Ohms (12,000) on both coils"
and not "Secondary is 12.0 Ohms on both coils"

Otherwise the secondary, for all practical purposes, would be dead (short circuited). Given that the coils work and the bike runs at all, it must be 12K Ohms.

Just me being anal this afternoon

Good on you for having the WG Coil Re-powering Mod already installed. Almost all of these vintage bikes benefit from this mod. The fact that you thought of the checking the grounding is a great sign of being on the right path. Check the connector crimps while you're at it and if in doubt clean them solder them... don't ask how know this.

Best of success.

Post edited by: bill_wilcox100, at: 2007/09/08 15:25

loudhvx, thank you and I will take your advice and get a timing light. I do intend to work on my bikes, current and future, and it only makes sense to invest in a good one. Do you have a recommendation?

Bill, yep, I did mean 12k, I had the tester on 1x1K. You're not being anal, I was being sloppy, thanks for the reminder of the importance in posting accurate data (as I sit here a little red in the face).

I will track down all grounds and connectors, period. I have read a lot posts on problems that turn out to be wiring and connectivity issues rather than component failures. She's and old bike, and while still many miles to go, stuff wears, corrodes, and becomes brittle. I think it's called maintenance:)

Thanks for all the help, you have all given me good direction, and I know I will resolve this "with a little help from my friends".

This is the one I've had for about 10 or 15 years.
Sunpro CP7519

It works very well on the Kaw ignitions. Not all lights work with all ignitions, but this has worked on everything I've tried it on. The only thing is that you have to put a piece of tape on the knob because if you bump it, the readings will be off.

The knob is calibrated for cars with distributors, so you have to do some math to get the numbers on the knob to correspond to the KZ timing values. Luckily, the KZ doesn't require usage of the knob at all (just leave it set to zero). Because of this, you could probably get away with a cheaper timing light (there is a similar version without the knob), as long as you are only using it on the KZ.

I'm sure there have to be cheaper, yet adequate, lights out there.