Which Plug Wire is Which?

1981 KZ440A LTD with no spark on one side. Checked for 12v at Yellow+Red and Yellow+Blue and only Yellow+Red passed so new IC Ignitor on the way. I pulled the coil and wires but how do I know which plug wire goes on which side?

1981 KZ440A LTD with no spark on right side. Tested IC Ignitor and found that only Yellow+Red had 12v, Yellow+Blue was way low so new IC Ignitor on the way. I pulled the coil and realized I don't know which plug wire went on which side. How can you tell or do the plugs fire at the same time?

Same time.

It sounds like you just wasted money on a igniter. This is a "waste spark" setup. Both plugs fire a t the same time. You have something else wrong.

Wasted spark ignition.

For some reason the vid gives an error when I clicked on it.

loudhvx wrote: For some reason the vid gives an error when I clicked on it.

Here is the link again. Or google, "how to use an automotive test light" and ENJOY!

Strange, now that I linked to it, it plays above and here.

Thanks for the info! I swapped out the IC Ignitor and have very strong spark at both plugs. One had no spark and the other had a weak spark. Bike fired right up. Got carbs off and bench synced them. Will pop them back on and see how she does. Thanks!

Thanks for the update! I really don't get why one had spark and the other did not, since the HV circuit runs through both plugs as shown in my pic. Perhaps it may have been weak enough that you were not seeing it in both plugs. I'm thinking that other things, plugs / connections were re-seated during your igniter change.
At any rate, you sound stoked after getting it running. Enjoy