what are 'Bad Igniter' symptoms?

PROBLEM
- I ride the bike for about 10 minutes then engine will die unless I keep it revved up to at least 3000 rpm.
- And when I keep it revved at 3000rpm at stop lights it is misfiring.
- if I get on the gas it accelerates FINE. But as soon as I back off on the throttle the bike will die unless I keep it revved to at least 3000rpm.

It's my 1980 kz1000 Z1 Classic.

It happened this afternoon. I had to nurse the bike to get home by never letting the revs fall below 3000rpm.

THEN about 20 seconds driving distance from my house the bike returns completely to normal -- idles fine, no misfiring, no need to run it at 3000rpm to stop it dying.

Could an intermittently bad igniter cause this?

I've never had an igniter go bad on me in my life so I don't know the symptoms.

NOTE
- battery is fine, almost brand new

I suspect the ignition coils may be the problem, even when new the coils were weak, add years and overheating and you could have this problem. www.z1enterprises.com sells replacement ignition coils, I think they can get you the 3 ohm Dyna ignition coils too.

Try changing the ignition sparkplug caps,and sparkplug wires.

If your bike has a mechanical ignition advancer(behind a CD sized cover on the right side of the engine) check to make sure it's working. With the engine off, see if it will twist and return to it's at rest position. If not ,remove it,clean and re-install it.

Light lubrication with either 3-in-one or sewing machine oil is about all it needs now and then.

newOld_kz1000 wrote:

PROBLEM
- I ride the bike for about 10 minutes then engine will die unless I keep it revved up to at least 3000 rpm.
- And when I keep it revved at 3000rpm at stop lights it is misfiring.
- if I get on the gas it accelerates FINE. But as soon as I back off on the throttle the bike will die unless I keep it revved to at least 3000rpm.

It's my 1980 kz1000 Z1 Classic.

It happened this afternoon. I had to nurse the bike to get home by never letting the revs fall below 3000rpm.

THEN about 20 seconds driving distance from my house the bike returns completely to normal -- idles fine, no misfiring, no need to run it at 3000rpm to stop it dying.

Could an intermittently bad igniter cause this?

I've never had an igniter go bad on me in my life so I don't know the symptoms.

NOTE
- battery is fine, almost brand new

I've had these exact symptoms on numerous bikes, including mine.

First time it was a coil. Second was one side of a dyna s pickup failed. As said, its deffinately an intermittant spark issue.

Best of luck.

MFolks wrote:

I suspect the ignition coils may be the problem, even when new the coils were weak, add years and overheating and you could have this problem. www.z1enterprises.com sells replacement ignition coils, I think they can get you the 3 ohm Dyna ignition coils too.

Try changing the ignition sparkplug caps,and sparkplug wires.

If your bike has a mechanical ignition advancer(behind a CD sized cover on the right side of the engine) check to make sure it's working. With the engine off, see if it will twist and return to it's at rest position. If not ,remove it,clean and re-install it.

Light lubrication with either 3-in-one or sewing machine oil is about all it needs now and then.

If I check the coils and they ohm-out correctly, and I'm getting the correct voltage -- what would be the next possibility?

This symptom is a bit on/off. Either the bike runs great -- or all of a sudden it needs to be at 3000rpm or higher at stop light or it will die -- then several minutes later it's back to running correctly.

Question is, would coil going bad 'sometimes work' then 'not work' then back to 'working fine' again like I'm experiencing?

I checked the ignition advancer last week, it is fine, clean as a whistle behind the cover, no oxidation anywhere, this was a garaged bike throughout its life thus far -- the advancer moves back and forth with no sticking at all.

You can check Igniter, remove one of each pair of spark plugs, ground against cylinder head, turn on ignition, touch a screw driver or magnet to pick up coil core, if good plug will fire, remember to have a charged battery.

Try using an inductive timing light around your plug wires, 1 at a time and watch for the light to become intermittent. Of course 1&4 Then 2&3 will be the same sides of the system. A faulty connection to the injectors could be similar to this. If a DVOM with the capabilities of measuring "Pulse Width" is available, you can back probe the wires at the injectors and see if it checks out. Or one at a time unplug each injector and use a Noid light. Harbor Freight has a set pretty cheap. But you will not have current to the injector your testing at the time so if it barely wants to run it might be difficult. Checking the OHMs of the Injector solenoids would be a good idea.
They have these inline spark checkers:
www.harborfreight.com/automotive-motorcy...rk-checker-4424.html
Here is the Noid Light set:
www.harborfreight.com/11-piece-noid-ligh...ester-set-97959.html You could use a Computer safe test light as well, or a regular test light if it has a LED bulb or low wattage incandescent.

Some more information:

Ignition Coil Primary And Secondary Wiring

Ignition coils on the 80’s Kz1000,Kz1100’s and Gpz1100’s are wired the same, that is as you sit on the bike, the LEFT ignition coil primary(small wires) are two wires, RED and BLACK. The secondary (or sparkplug wires) go to #1 and #4 sparkplugs.

The cylinders are numbered left to right as you sit on the seat; #1,#2,#3, and #4.

For the RIGHT ignition coil, the primary wires, again are two wires, RED and GREEN, with the secondary going to #2 and #3.

The RED wire gets it’s voltage from the run/stop switch on the right handlebar switch pod.

The BLACK and GREEN wires connect to the IC Igniter(if the bike has the Kawasaki supplied electronic ignition) it actually gives the coils their grounds to fire the sparkplugs.

Primary(small wires) side of the coils will read between 1.8 to 3.0 ohms.

Secondary(sparkplug wire ports)side of the coil will read between 10.4K to 15.6K ohms. These ports are wired together, so it makes no difference which is used, as long as the correct coil to sparkplug configuration is followed.

To stress the ignition coils, take a hair dryer, heat the coils and see if the ohm readings change from cold to hot . If they do, it’s time to buy new coils.

Keep in mind, the wiring is reversed for the 550’s 650‘s and 750‘s, that is the RIGHT coil primary will be two wires, RED and BLACK with the secondary(sparkplugs) going to #1 and #4.

The LEFT coils primary wiring would be again two wires, RED and GREEN, with the secondary(sparkplugs) going to #2 and #3.

These engines have what is known as a “Wasted Spark” that is, a sparkplug will fire during an exhaust stroke. It does no damage and many other motorcycle engines have this design.

MFolks wrote:

Some more information:

Ignition Coil Primary And Secondary Wiring

Ignition coils on the 80’s Kz1000,Kz1100’s and Gpz1100’s are wired the same, that is as you sit on the bike, the LEFT ignition coil primary(small wires) are two wires, RED and BLACK. The secondary (or sparkplug wires) go to #1 and #4 sparkplugs.

The cylinders are numbered left to right as you sit on the seat; #1,#2,#3, and #4.

For the RIGHT ignition coil, the primary wires, again are two wires, RED and GREEN, with the secondary going to #2 and #3.

The RED wire gets it’s voltage from the run/stop switch on the right handlebar switch pod.

The BLACK and GREEN wires connect to the IC Igniter(if the bike has the Kawasaki supplied electronic ignition) it actually gives the coils their grounds to fire the sparkplugs.

Primary(small wires) side of the coils will read between 1.8 to 3.0 ohms.

Secondary(sparkplug wire ports)side of the coil will read between 10.4K to 15.6K ohms. These ports are wired together, so it makes no difference which is used, as long as the correct coil to sparkplug configuration is followed.

To stress the ignition coils, take a hair dryer, heat the coils and see if the ohm readings change from cold to hot . If they do, it’s time to buy new coils.

Keep in mind, the wiring is reversed for the 550’s 650‘s and 750‘s, that is the RIGHT coil primary will be two wires, RED and BLACK with the secondary(sparkplugs) going to #1 and #4.

The LEFT coils primary wiring would be again two wires, RED and GREEN, with the secondary(sparkplugs) going to #2 and #3.

These engines have what is known as a “Wasted Spark” that is, a sparkplug will fire during an exhaust stroke. It does no damage and many other motorcycle engines have this design.

I'm going to try the hairdryer test because simply ohm'ing the coils then ensuring they're getting the right voltage, I have just realized after reading your post -- doesn't check for the 'heat' influence. Thanks for that insight.


So no one had commented on the igniter as being a possible problem.

I have a question then. I've never fixed a coil issue. If one of the coils was bad -- why would after 20 minutes of riding today did the bike go back to normal?

If not already done, would assure valve clearances are within specs.

Too tight valves may cause compression loss as engine warms.

Would also assure integrity of ground where negative battery cable attaches to rear of engine. And that battery terminal connections are clean and snug.

Imo, seems unlikely that both coils would simultaneously fail when warming.

Would also assure that the igniter's ground wire is functional and isn't loose or corroded.

Good Fortune!

Patton wrote:

If not already done, would assure valve clearances are within specs.

Too tight valves may cause compression loss as engine warms.

Would also assure integrity of ground where negative battery cable attaches to rear of engine. And that battery terminal connections are clean and snug.

Imo, seems unlikely that both coils would simultaneously fail when warming.

Would also assure that the igniter's ground wire is functional and isn't loose or corroded.

Good Fortune!

Good call on the valve check, I have done that and all were in spec. The + and - connections are sound, tight and corrosion-free.

Patton have you ever heard of a coil(s) that is failing but only at low rpms, and suddenly after a notable ride of 20 minutes (and it was in the upper 60s and sunny today here also)-- after 20 minutes the coil failure vanishe -- have you ever heard of a coil that was bad but only sometimes? Or when coils fail are they just *done* and they don't mysteriously start working fine again? I figured that a coil failure would be black and white -- it fails and that's it. But I have zero experience with coil failures.

A forum member "Loudhvx" has made a igniter substitute using off the shelf GM electronic ignition modules.

This works only with the bikes having the mechanical ignition advancer like your bike has.

home.comcast.net/~loudgpz/GPZweb/Ignition/GPZgmHEImod.html

Drop Lou a line and ask if he has any thoughts about your IC igniter possible intermittent failure.....

I've been following this thread, and didn't really post anything because others have pretty much covered most of what I would have suggested.

As Tek9ine suggested, this type of symptom can be caused by many, many things, unfortunately.

If I got a bike out of the blue that had these symptoms, and I was unfamiliar with the bike's history, here's where I'd start.


Look for obvious things: vac leaks, fuel leaks, fuel flow, etc., but nothing real in depth.
Then:
Compression check.
Valve clearance check. (Ala Patton)
Then I'd try to verify the ignition using Motorhead's suggestion of using a timing light. That will tell you the timing, but will also tell you if you have false triggers, or ignition drop out etc. When the bike is idling, and you hear a little puff or hiccup, note if the timing light shows the rotor at a different angle or if the light just doesn't light. If the rotor appears to have a ghost image of it pointing the wrong way, then you have crosstalk in the ignitor.
If the ignition has a problem, then you have to fix that before anything else.
Then I'd move on to carbs/fuel/vacuum etc.

I like troubleshooting and finding the actual problem positively, but usually it's way faster to just fix/replace things systematically, but may cost more. 30 year old coils are high on the list of likely failures. Then would come ignition switch, kill switch, dirty fuse connections, bad-wiring or connectors. I think igniter comes in almost last, but not by far. I've only seen about two ignitors go belly up. They were not intermittent, just flat lined. But I'm sure they can be intermittent too. Here, again, is the link Mfolks gave:
home.comcast.net/~loudgpz/GPZweb/Ignition/GPZgmHEImod.html

When that type of ignition (early 80's factory Kawasaki) is working properly, Lemo32's test does work for creating spark, so that is a good first check.

I've only ever been stranded by old coils dying after they got wet a day earlier. Both died within a few miles of each other. So even if they worked fine, I'd probably putting on some new Dyna gray 2.2 ohm coils. Just make sure the connections have at least 1/4" clearance (they like to come into contact with frames).


So sorry, I'm basically just rehashing what everyone else already said.