'80 kz550 ignition tests

Hi there, I've owned a '77 kz1000 for 7 or 8 years and I have just recently joined the forum because I've purchased a kz550 that is in need of some repair. I'll try to get some pictures up soon.

It turns over readily but has no sign of a spark. I replaced the cracked coils with good used ones including plug wires.

At the moment I'm unsure if the problem lies with the ignitor or the pickup coils. I performed the resistance test laid out in the manual on the 4-pole connector between the pickup coils and the ignitor, testing the resistance between each pair (1/4 and 2/3). The voltmeter doesn't seem to be affected, it shows no resistance no matter how I apply the voltmeter leads. The voltmeter is completely unaffected. Is the test this simple and does this mean the pickup coils are bad?

Also, after I obtained an impact driver I removed the pickup coil cover and did the simple ignitor test laid out in the manual. With one of each pair of plugs removed I touched the pickup coil with a screwdriver. This brought the first spark I have seen to the bike, but only 3 sparked and not 4, although I did touch both pickup coils. According to the manual this would suggest the ignitor is also bad.

Are these tests independent of each other? In other words, if the pickup coil is bad would that have affected the ignitor test?

One other thing. The bike has a plunger-type clutch safety switch but I had to replace the old broken clutch assembly with a used one from a kz that didn't have the switch on it. Can I just remove this switch?

Thank you!

First, welcome to the site!

Second: the clutch switch is easy to bypass. The switch has two wires to it. All you need to do is connect them together somehow.

The test by tapping the pickups shows one of them is at least connected and working. However this should have shown up as good in the ohm-tests for the pickups. Somehow your resistance testing is not being done properly.

The igniter tests are only valid if the pickups are good. If you don't know if the pickup is good, then you can't tell if the igniter is good by tapping the pickup.
Same goes for the ignition coils. If a coil is bad, tapping the pickups won't tell you if the igniter is good or bad. Luckily, since it's a 4-cylinder bike, you can test everything by doing some swapping.

You said #3 sparked, so you know the 2-3 coil is good, the 2-3 pickup is good, and the 2-3 circuit in the igniter is good. Or at least you know they are good when the plugs are out in the open.

The next step is to swap the green and black wires at the coils. Then do the tapping test again.
If #4 sparks, then the 1-4 coil is good.
If #4 does not spark, then the 1-4 coil is bad.
If #3 sparks, then the 1-4 pickup is good, and the 1-4 igniter circuit is good.
If #3 does not spark, the problem may be the 1-4 pickup or the 1-4 circuit in the igniter.

And as always, any problem can also just be an associated wireing problem, ie broken wire etc.

Give the results here, and I'll tell you how to determine the pickup versus the igniter.

Just to clarify, are you getting NO resistance or infinite (lazy eight) resistance?

I'm getting no resistance at the connector. The test seems pretty simple in the manual so I don't know how I could be doing it wrong, that doesn't mean I'm doing it correctly though.

Thanks loudhvx, I'll try swapping the coil wires later today and get my results posted.

I have a KZ500/550 & ZX550 repair manual in .pdf format covering 1979-1985 models. I found it on the internet; does the site have any copyright rules? I'll post it on the web-site if it won't cause any problems.

508_ponshock wrote:

I'm getting no resistance at the connector. The test seems pretty simple in the manual so I don't know how I could be doing it wrong, that doesn't mean I'm doing it correctly though.

Thanks loudhvx, I'll try swapping the coil wires later today and get my results posted.

I have a KZ500/550 & ZX550 repair manual in .pdf format covering 1979-1985 models. I found it on the internet; does the site have any copyright rules? I'll post it on the web-site if it won't cause any problems.

That's probably the manual I have. It's already been posted in several places, so I wouldn't bother posting it here just in case.

Back to the resistance check.
Yellow to red should measure 450 to 460 ohms.
Black to blue should also measure 450 to 460 ohms.
Make sure you're on the right scale unless it's automatic.

I did the tests you recommended and the 1-4 coil checked out, the #3 plug didn't spark after the green and black wires were switched suggesting, as you said, the 1-4 pickup coil or ignitor circuit is bad. How do you determine if the problem lies with the pickup coil or the ignitor?

I looked at the direction booklet for the ohm-meter I have (when all else fails..) and it said a reading of 1 meant infinite resistance or that a higher scale should be selected. So it appears the resistance is infinite because it reads 1 at all scales.

508_ponshock wrote:

I did the tests you recommended and the 1-4 coil checked out, the #3 plug didn't spark after the green and black wires were switched suggesting, as you said, the 1-4 pickup coil or ignitor circuit is bad. How do you determine if the problem lies with the pickup coil or the ignitor?

I looked at the direction booklet for the ohm-meter I have (when all else fails..) and it said a reading of 1 meant infinite resistance or that a higher scale should be selected. So it appears the resistance is infinite because it reads 1 at all scales.

The meter may be faulty, or maybe you're not making contact with the wires somehow?

To test whether it's the 1-4 pickup or 1-4 igniter circuit:
Put the coil wires back to normal (black to 1-4 coil, green to 2-3 coil).
Now it's a little tricky. You need to swap pickup wires in the connector at the igniter. You need to swap black with yellow, and blue with red. You can do the swap on either the igiter side of the connector or the pickup side of the connector. This effectively swaps the pickups. Now do the tap test. If #3 sparks, then it's the igniter that is bad. If #4 sparks, it's the 1-4 pickup (the black-blue pickup) that is bad.

(Or a wire is bad. We need to get the ohm-meter working to hash out the wiring.)

Also, in case someone messed with the pickup plate, read this thread:
kzrider.com/index.php?option=com_kunena&...d=4&id=134605#134609

If the igniter is bad, consider this:
www.geocities.com/loudgpz/GPZgmHEImod.html

I switched the pickup wires and the result was a sparking #4 and non-sparking #3. So the #4 pickup is bad. I can't find any problems in the wiring.

Can these pickups be replaced individually? I've seen complete pickup coil units including the plate and wires on e-bay for $10 but if I could buy new that would be preferable. Are the pickup coils available new?

Thanks for you help!

Don't know if they are available, but you can use actual pickups from pretty much any KZ that has that type of ignition. Basically if you can find any 1979 to 1983 KZ electronic ignition plate, and the pickups look exactly like the ones on your bike, you can use them.

There were other types that look different. You can't use those.

Refer to that link on the pickup magnets to reassemble your new plate if the one you get is from a 1000 or 1100. Your timing plate is basically the same as the ones on 650's and 750-four cylinders. Those are a direct swap except fot eh length of wires. You may have to splice some wires as there were variances on wire length even among the 550's.

I'd still like to see a confirmation with the ohm-meter somehow. Another test is to take two safety pins and poke them into the blue and black wires right at the pickup itself, and do a resistance check there. If it comes up around 450 ohms, then the pickup is ok, and the wire is bad. A simple splice may fix it.

Good luck hunting if you go the ebay route. I've had really good luck on ebay for ignition plates.

random thought, 1-4 and 2-3 pickups are just that. like points they cause field collapse simotaniously (SP) and spark at 2 cyls at each crank revolution. if a coil provides spark at one plug and not the other, coil/wire/cap/plug are suspect. Neandritol approch. disconnect failing coil from system. lay both plugs on grounds. jump one side of primary coil to ground and strike other side w/ battery voltage. both plugs should spark. if not, swap caps/plugs. your' problem may be 2-3 fold, start with the easiest. Luck g

gane wrote:

random thought, 1-4 and 2-3 pickups are just that. like points they cause field collapse simotaniously (SP) and spark at 2 cyls at each crank revolution. if a coil provides spark at one plug and not the other, coil/wire/cap/plug are suspect. Neandritol approch. disconnect failing coil from system. lay both plugs on grounds. jump one side of primary coil to ground and strike other side w/ battery voltage. both plugs should spark. if not, swap caps/plugs. your' problem may be 2-3 fold, start with the easiest. Luck g

Not really sure what you're getting at. His issue wasn't that #4 would fire without #1 firing. His issue was that #3 would fire and not #4. Those are two seperate circuits entirely.

The pickups only provide low-level signals to the igniter. The igniter is what controls the ignition coils.

I'm bidding on a pickup coil assembly on e-bay right now, I'll be sure to let you know how things turn out. Thank you.