Ignitor test question

[Bizcocho]

I've found the Clymer ignitor test on the forum. I've also found that people have power-loss at highway speed with bad ignitors. Does the on-off spark test prove that the ignitor will be OK at high speed?

Last week I found a test where a wire is rubbed down a file, and I thought it might be better for the high-speed power loss. Today I can't find it. Does anybody know where it is?

1980 GS 550E

Thanks,

Rich

[Jaguarjoe]

I don't think the file test works with an ignitor. It works well with a points ignition though.

[SPARKSS]

I've found the Clymer ignitor test on the forum. I've also found that people have power-loss at highway speed with bad ignitors. Does the on-off spark test prove that the ignitor will be OK at high speed?

Last week I found a test where a wire is rubbed down a file, and I thought it might be better for the high-speed power loss. Today I can't find it. Does anybody know where it is?

1980 GS 550E

Thanks,

Rich

Hi there Rich. If what you're doing to test momentarily is to briefly connect a 1.5 volt battery across the pickup connector (pickup disconnected) and THIS triggers the ignitor, then the trick using the file (straight cut preferred) is to make the same connection except that instead of momentarily "touching" the battery on one side, you connect to the file and then run the wire down the length of the file........this rapidly makes and breaks the input and should result in a more continuous triggering. Old school but effective if you don't have anything else.

That said, how is it that you plan to determine whether the ignitor (or the rest of the primary or secondary side of the ignition is failing, using this sort of test? Reason I say this, is that in order to determine high speed problems with the ignition (once fuel or other basics have been ruled out by other testing), it's common to use an ignition scope (HV oscilloscope) coupled to the ignition secondary WHILE operating the engine UNDER LOAD or under the conditions where the symptoms occur. This is, obviously, done really using the existing pickup as you also want the engine running and synched to the ignition..........with the spark operating under compression AND combustion.
Obviously, crude testing using something like a file won't produce meaningful results (no matter what sort of ignition switching was planned).

Operating an ignition with a plug in open air, by temporary means is a means to effect a basic go-no test only and is not always a true indicator of what happens under dynamic conditions - however a solid blue spark produced in this manner, repeatedly, is a good sign.

[Bizcocho]

Thanks SPARKSS. This is interesting and makes sense. I'm not quite sure where to go next, but I have since become pretty sure it's missing on just one cylinder at speed, probably eliminating the ignitor, and I think the coil.

I'm going to change the spark-plug cap today. It has a little corrosion on the threads where it screws into the wire. The other three looked like new - well, why not, they're only 28 years old.

[SPARKSS]

Thanks SPARKSS. This is interesting and makes sense. I'm not quite sure where to go next, but I have since become pretty sure it's missing on just one cylinder at speed, probably eliminating the ignitor, and I think the coil.

I'm going to change the spark-plug cap today. It has a little corrosion on the threads where it screws into the wire. The other three looked like new - well, why not, they're only 28 years old.

Sounds logical to me. Sometimes diagnostics have to be dictated by what's available and limited by bucks 'n time. Doesn't hurt to know the theory but I've often found myself with nearly nothing and the need to fix.......breeds creativity (both productively and with directed-at-no-one comments!)!