You must be friggin' kidding me... (coils)

[Tenrilid]

I'm having an issue w/ my system as well. I'm just not getting any spark but i've tested my signal generator, coils, i'm getting 11.8v at the coil power wire but still no spark!! I've taken out the plugs to check gaps and those are fine but when I hook up the tester to see if the plugs are sparking and no juice . I don't know how I can test the ignitor but the one I am using is used which I got from ebay and was told it was off a running bike. Not sure what else to do.

[mike_of_bbg]

Well, you're thread-jacking a little bit, and you might want to start a new thread so your issue can get some individual attention. But here's some information which may be useful to both of you.

First, the coils should always be getting +12V (more or less) when the ignition is on. The ignition's effect is at the GROUND of the coils. They start grounded, which builds up the electric field through the coil primary loop, which also just-so-happens to surround the secondary loop as well. When the spark is needed, the ignition removes the ground from the coils. The field collapses and induces the current in the secondary loop. The secondary loop is much larger, so the voltage is also much larger (although the current is much smaller). You'll notice that each coil has an orange/white +12V feed, but have different colors on the ground wire. They're different circuits. That's the lead which needs to be swapped to test to see if an issue follows the lead or stays with the same coil. For that test you're just looking for spark, not trying to run the motor. It doesn't matter that the spark will not be at the correct time. Just lay the plugs against the head so that they're grounded, with the wires connected, and look for spark.

The ignitor is what grounds (and pulls the ground from) the coils on the factory electronic ignition systems. Under the ignition cover there's a plate with a set of pick-ups called the signal generator. When the magnet on the rotor passes by these pick-ups as the motor turns, it creates a little spike of voltage which is sent to the ignitor and causes it to trigger the spark. The sig gen and coils are passive components and are usually tested easily with an ohmmeter. There's a valid range for each of the pickups in the sig gen, but it does vary between certain models. You'll probably want to check a manual.

If 1&4 are firing and 2&3 are not, you swap the grounds, then 2&3 are firing, then both coils are likely fine and the issue is somewhere in the wiring up to the coils. If 1&4 keep firing, then you might have bad coils.

In my picture below I showed the coil plug, but swapping the plugs won't actually help in my case, because only the +12V is going through them (the orange/white wires). I've already hooked up a Dyna ignition, so the white and black ground wires with the blade connectors are what I would need to swap for this test.

I'm having an issue w/ my system as well. I'm just not getting any spark but i've tested my signal generator, coils, i'm getting 11.8v at the coil power wire but still no spark!! I've taken out the plugs to check gaps and those are fine but when I hook up the tester to see if the plugs are sparking and no juice . I don't know how I can test the ignitor but the one I am using is used which I got from ebay and was told it was off a running bike. Not sure what else to do.

What tester are you using to check for spark? Just lay the plug against the head as previously described. You might need to be in a closed garage to see it. Noticing the spark in directly sunlight is sometimes tough.

[FiremanBob]

Igniter test with coil removed?

So Monday I had disconnected the coil for cylinders 2-3 suspecting that the wiring to it was bad, and the wiring was good. Now that coil is disconnected and I'd have to re-solder the connections to hook it up again.

I want to test the igniter, but I can't use the method in the Clymer manual because one coil is not connected.

This morning I connected a voltmeter with the positive lead hooked to the black/white wire (that leads from the igniter to the coil) and the negative on a ground. I believed that if I cranked the engine, the igniter would send voltage that I could measure on the meter. There was nothing.

This means either I set up the test wrong or the igniter is bad, or else what?

Is there another way to test the igniter that would yield a definitive result?

Thanks.

[mike_of_bbg]

Please see my post from yesterday. The ignitor controls the ground, the coils should always be getting ~+12V through the orange/white wire. Why don't you crimp/solder in some blade connectors instead of the whole wire? That should make troubleshooting much easier. What's the primary resistance of the coil?

Most multimeters have very pointy tips which can pierce the insulation on wires so they don't need to be disconnected for testing. Highly recommended to wear work gloves though in case you miss or go too far

[FiremanBob]

Thank you, Mike. So if I understand it now, the o/w wire supplies constant 12V to the coil, and the igniter (once the signal generator closes the circuit) provides the ground allowing current to flow through the primary windings in the coil, which is suddenly interrupted, triggering the induction in the secondary winding?

I was able to use alligator clips to jury-rig the o/w and b/w wires back onto the coil. Assuming they hold, I should be able to test the igniter now. But I don't know which wires from which connector I should use. (Yes, I know I'm stupid.)

The linked photo shows the electrics under the right side cover. There are two large white connectors. One large connector is under the black rubber shield, and another is uncovered. Which one do I use to test the igniter?

Where is the igniter, anyway? I can't see it from either side. The photographs in the Clymer manual really suck - too small and too dark.

If anyone is willing to talk me through this while I'm at the bike, please call at Four-oh-1 Two-5-eight Seven-6-one-5.

Thank you.

[cowboyup3371]

Look underneath your air box...that's where the one on my 81 550t is at.

[FiremanBob]

Mystery solved

As another thread says, "You can't fix stupid," and as Forrest says, "Stupid is as stupid does." It's a mystery of medical science that I can walk and breathe at the same time.

The reason the engine was running on two cylinders after installing the coil relay mod is that I bought the wrong kind of relay. The 5-pin relay I bought switches between the two outputs, 87 and 87a, instead of running both at the same time. When one coil got juice, the other didn't, depending on whether the ignition was switched on or off. This also means that for two days it's been running the battery down, although the current draw was too low to hurt anything.

Tomorrow I'll go buy the correct relay and all will be fine, provided that I can make the solder connections for the coil primary wires.

Also, my valve cover gaskets came in today so this weekend we'll check the valves and install the new tach drive gear. I hope that will go smoothly.