Can Ignitor fail to fire one coil?

[Marc Warner]

Hi Guys:
Im troubleshooting a no spark situation on my 1982 1100E. I have no spark form my left coil - so no spark to cylinders 1 and 4. Switching the coils shows the same result, so I believe both my coils are still OK. I have power to all four terminals of the coils (+ and -) with the key on so I am looking at the "ignitor" as a possibal problem. Is it possibal for the unit to fail in such a way as to not fire one coil but continue to fire the other? Any testing I can do of this unit to help find the actual fault? Any guidence would be greatley appreciated. Thanks in advance.

[tom203]

Hi Guys:
Im troubleshooting a no spark situation on my 1982 1100E. I have no spark form my left coil - so no spark to cylinders 1 and 4. Switching the coils shows the same result, so I believe both my coils are still OK. I have power to all four terminals of the coils (+ and -) with the key on so I am looking at the "ignitor" as a possibal problem. Is it possibal for the unit to fail in such a way as to not fire one coil but continue to fire the other? Any testing I can do of this unit to help find the actual fault? Any guidence would be greatley appreciated. Thanks in advance.

Sure, it's possible but it's also possible that signal generator (right side on end of crank) isn't sending a signal to ignitor- maybe bad connection/wiring or a little coil has failed. Follow the link to Basscliff's site for some good tips on continuing the testing you've started.

[Steve]

First of all, WELCOME.

Follow the link to Basscliff's site for some good tips on continuing the testing you've started.

BassCliff will be along shortly with the full welcome package, so here is the link to what tom mentioned:

http://members.dslextreme.com/users/cbsaunders/gs/Repair_and_Fault_finding_GS1000G_Ignitor.pdf

.

[Homie]

Hi Guys:
Im troubleshooting a no spark situation on my 1982 1100E. I have no spark form my left coil - so no spark to cylinders 1 and 4. Switching the coils shows the same result, so I believe both my coils are still OK. I have power to all four terminals of the coils (+ and -) with the key on so I am looking at the "ignitor" as a possibal problem. Is it possibal for the unit to fail in such a way as to not fire one coil but continue to fire the other? Any testing I can do of this unit to help find the actual fault? Any guidence would be greatley appreciated. Thanks in advance.

Okay, since you switched your coils and got the same results, I'm going to assume that the coils are okay. So, I would check the following:

First I would test the signal generator. Disconnect the two pin connector from where it connects to the ignitor. Using an Ohm meter test the resistance between the two wires of the signal generator. It should be 250-360 Ohms. If its above or below this amount the signal generator is faulty.

Next test the ignitor itself. Remove spark plugs #3 and #4 and ground them against the cylinder head. With the connector from the signal generator still disconnected do the following: On the ignitor side of the connector from the signal generator there are two wires, blue and green. Take the red (+) probe of your Ohm meter and contact the blue wire. Then take the black (-) probe of your Ohm meter and contact the green wire. As soon as you touch the green wire #3 spark plug should spark. Reverse the polarity of your probes putting the red probe on the green wire and the black on the blue. As soon as you touch the black probe onto the blue wire #4 should spark. If the spark plugs fail to spark while conducting this test your ignitor is faulty.

Hope this helps you find your problem. Now grab your Ohm meter and go test your ignition!

[Marc Warner]

Wow, Fast, cool help. Thanks!!

Just the kind of stuff I was looking for, and Fast!! Thanks Steve, and Old School. Really appreciaite the guidence. I now have homework for tonight. Ill let you know what I find. Thanks again!! OOPs, forgot Tom - Ill check-out the SG as well. Thanks!!

[Matchless]

Once you have proved the fault to the ignitor then its possible that one of the two output transistors are blown. These can be replaced on some ignitors.

[Marc Warner]

All right everyone:

With you're kind help (and thanks again!!) Heres what I found in my further testing. I first tested the resistance through the Signal Generator and found it within the suggested specks (thanks old skool) at 330 ohms.

Next I tried to fire spark wires with My fancy plug tester, and couldn't make them fire either coil as described (ohm meter on blue and green wires from the ignitor). I tried with key on and off, as this wasn't specified in your instructions (hey, don't beat yourself up over this). Next I turned on the key and engaged the starter and, as before, had a nice blue fat spark on 1 & 4 and nothing on 2 & 3. So I'm thinkin ignitor more than ever, but heres the question.

Could it be that the ignitor works with the starter engaged (firing 1 & 4) but then doesn't ignite that coil with the described test?

Anyway, gotta precious week off startin next wednesday to ride around New England and I want my (70,000 mile, 23 year old) favorite motorcycle to do it on, so I think I'm sprining for a used Ignitor on ebay tonight. I'd still be into hearing everyons thought and suggestions though - I'm still not positive Im on the right track. This all started with me removing, fixing (by epoxying back in two of the magnets - works great!!) the starter from what was a pretty good running bike, and changing over the battery - so I'm not sure about the cause of the ignitor failure - i.e. -= why now?

Anyway - Thanks again for all the help and ideas - no way I could undertake some of this stuff without all your support. Great forum!!

Marc

[Matchless]

Could it be that the ignitor works with the starter engaged (firing 1 & 4) but then doesn't ignite that coil with the described test?

Yes your question is valid, but it is more likely you have not done the tests correctly and it is more likely that a spark missing or weak situation occurs with the starter motor turning and pulling current from the battery and the battery is not fully charged or fails a load test.

Have you checked for 12V on the coils with the ignition on? If its too low compared to the battery voltage which should be about 12.5V if fully charged AND you starter is drawing excessive power from the battery when turning (also measure while starter is turning) then it could cause a problem with the spark.
A bad battery (jump it with a car battery - with the car engine not running to prove)
Poor wiring connections, coil, ignitor, power wire connectors from the main fuse back to the ignition and via the ignition fuse to the kill switch and back to coils and ignitor. A low voltage at the coils usually confirm this, meaning a high voltage drop between the battery and the power at the coils.
Then as said before a possible output transistor blown in the ignitor for coil 3 & 4. Do the ignitor test as per the information on Basscliff's site to prove this.

[tom203]

Marc Warner said..."Anyway, gotta precious week off startin next wednesday to ride around New England and I want my (70,000 mile, 23 year old) favorite motorcycle to do it on, so I think I'm sprining for a used Ignitor on ebay tonight. I'd still be into hearing everyons thought and suggestions though - I'm still not positive Im on the right track. This all started with me removing, fixing (by epoxying back in two of the magnets - works great!!) the starter from what was a pretty good running bike, and changing over the battery - so I'm not sure about the cause of the ignitor failure - i.e. -= why now?"


70 k, wow! Try this Matchless test;Remove spark plug #3, reattach plug wire and hold plug body against engine (so it can ground out); Remove signal generator cover,then with ignition and kill switch on, flick a small screwdriver blade across the face of the signal coil for #2 and #3 (this is what that tab on rotor does), any spark to #3?
Before venturing out in the NE wilderness, doublecheck your charging system to confirm its wellness. Personally, I'm skeptical of epoxying magnets in starter motors- there are large forces trying to twist things and the motor spends its quiet time in 200+ heat.

[Marc Warner]

Thanks again for the thoughts:
Matchless - it seems to me that if a low voltage problem were present I'd have the opposite result (no spark with the starter, but spark with the "matchless test"). Ill get some voltage readings tonight - good advise again. It's very well possibal that I'm misunderstanding the test proceedure, but it seems in essense to be jumpering the blue and green wires across the Ignitor siide of the signal generator connecter with the key on and killswitch off, which I think I got right.

Tom: I actually made a similar starter repair on two of my (4) magnets at least ten years ago - this time I had to epoxy the two I had not done before - I think the key is getting magnets and houseing REALLY clean with dremmel and then acetone - I'm comforted by the fact that failure doesn't strand me anywhere - as I've grown quite profficient in "bump-starting" over my lenngthy cyclying carrer. Thanks for your comments.

P.S. realized aftyer I posted that my favorite motorcycle is actually 29 years old - Math is hard!!

Marc

[Matchless]

It's very well possibal that I'm misunderstanding the test proceedure, but it seems in essense to be jumpering the blue and green wires across the Ignitor siide of the signal generator connecter with the key on and killswitch off, which I think I got right.
Marc

Marc,
The proper home ignitor test is to generate a pulse to the ignitor in place of the signal generator. The manual procedure could be done by using a 1.5v battery or the internal battery of your multimeter when set to the diode test position. The ignition on requirement is to ensure the coils and ignitor are getting 12V.
Getting spark on at least one coil (the one that sparks when turning with the starter) this way means you did the test correctly. If no coils spark you are most likely not doing it correctly.
Which procedure or tutorial were you following to do the test?

[Marc Warner]

I'm not proud of this, but....

Hi Everyone:

I retuned to my bike friday after wotrk with replacement ignitor in hand and went to swap it out for testing. I realized that, after diagnosing a broken wire at the begining of my electrical "saga", I had cut it on both sides of the four way connector (it was the white grounding wire that runs from ignotor, thru the 4 pin conector and up to the "-" side of the left coil), and then ran a new paralel wire but coneccted it to the "coil side" of the connector rather than the "ignitor side". This had led to my accurate testing of the continued no firing condition of this coil and the inaccurate diagnosois of the ignitor at fault. 5 minutes of soldering in the wire corrected the problem and the bike runs like new. The upside is the knowledge I gained, with all of your kind help, in the workings of my primary ignition, and in all the preventive degreasing and cleaning of my wiring harness and connectors, as well as the replacement of my plug boots, etc - all long overdue on my machine.
Anyway - Im off for yet another week-long unplanned ramble through New England on my precious week off and wanted to again say thanks to everyone. Ride safe and have fun!!
Marc

P.S. - Mathless - one of the bikes in my stable is a 1949 AJS 16MS - the 350 single with the (new that year) candlestick rear suspesion. Its a beautiful bike that I bought in boxes in 1992, and am less than 10 parts away from completing so I can actually start riding it around. If you're profficiant, I may pick your brain on that topic someday. Thanks again.

[Matchless]

Glad you got it sorted. As you said you now know how it works and you also know for sure you have repaired it!

PM me some pictures of the AJS when you get back.

[BassCliff]

Hi Mr. Marc Warner,

Sorry I'm late to the party.

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BassCliff