Weak spark on cyl 3 & 4

[kdurfee]

3 years ago I put in new accell coils, with a relay to run power directly from the battery instead of the ignition switch.

I currently have a week spark on cylinders 3 & 4. There is a spark, but barely. I used an in-line spark tester to check. I know that the coil or line in question is the left side. It's worse when the bike is cold, get's better when the bike warms up. It comes and goes, like some ghost is flipping a switch and it goes from strong idle, to missing and sputtering. I think I can figure out how to do the electrical tests, but it's not my strong suit. I'm just wondering if anyone has had this symptom before.

Thanks.

[kdurfee]

So -

I dug into it. I switched the coils; not an easy job. It didn't make a difference, cylinder 3 and 4 still have a weaker spark and miss frequently. I also switched the ignition modules, no change. It's dark out now, so I guess tomorrow I will move the spark plug wires around, and see if any of them are defective. I wouldn't be surprised if the spark plug wires are the problem, because I was a bit rough on them when I put them together. If they aren't the problem, then would it be the pulse coil?

[WingAdmin]

So -

I dug into it. I switched the coils; not an easy job. It didn't make a difference, cylinder 3 and 4 still have a weaker spark and miss frequently. I also switched the ignition modules, no change. It's dark out now, so I guess tomorrow I will move the spark plug wires around, and see if any of them are defective. I wouldn't be surprised if the spark plug wires are the problem, because I was a bit rough on them when I put them together. If they aren't the problem, then would it be the pulse coil?

Or the plugs? Eventually you'll find it when you swap enough parts.

[kdurfee]

It ended up being a spark-plug wire. Problem fixed. I learned how to use an ohm-meter in the process.