power from coil question gs1100E

[willem]

i have no juice coming OUT of the coils...
yes, i am a rank amateur...
that out of the way, i'm getting no spark to the plugs, i have juice to the coils, but none coming out of the coils. if i miswired the leads coming from the generator, could that have blown them?
my bike is a hybrid '81 gs750e (vin gs75x501***) with an '83 1100 motor, so the wiring is squirrelly at best.
thanks for any help at all.

[chef1366]

Which wiring harness are you using? Get the manual for that harness, a multimeter and test light. Have a go at it.

[almarconi]

I would only expect to see voltage coming from the coil when it is firing. For example, If you connect a test light up to the 1-4 coil (the signal wire) and turn the crank past the 1-4 sensor, the ignitor should send a signal to the coil and the test light should light up. The spark plugs should then give off a spark. As the crank continues around past the 2-3 sensor, the ignitor should send a signal to the 2-3 coil and then the 2-3 plugs should spark.

The service manual has a procedure to test the ignitor. I don't remember off the top of my head how it is done but you use the probes on a VOM meter to connect the wires in the ignitor, touch two in a certain order and 1-4 will fire, touch the other two and 2-3 will fire.

Without providing any history about the bike it is difficult to know if the ignitor is even any good. Did the bike used to run and then stopped working after you did something.

The generator (part of the charging system) leads hook up to the rectifier/regulator and not directly to the ignitor (part of the ignition system). You should test the resistance of your coils, both primary (3-5ohms) and secondary resistance to make sure they are within spec. If you need to test the charging and ignition components you should look at the stator paper and/or a service manual.

[Steve]

In spite of all the glory they might receive, a coil, is just a transformer.
Two coils of wire that are near each other with different number of turns in each coil.

Testing a transformer (coil) is rather easy. Use the OHM function of your multi-meter across the input terminals, you should get 3-5 ohms, as almarconi mentioned. The output termals are the spark plug leads. Connect your ohm meter probes, one to each plug terminal, you should get 20-30,000 ohms, depending on your particular model. This gives you basic condition. You might have a problem that shows up when the coil gets hot, but you can check it the same way when it gets hot. If your numbers are greatly different, you have a bad coil.

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