Coil Snapping/Discharge Issue

[larson7]

Hello,

I just finished adjusting my valves and installing a Dyna-S ignition system (coil and pickups). The bike fired right up and idles fine, but I noticed a few things. The most troubling issue is that on my left coil(1 and 4) I can hear what would best be described as a spark discharging which seems to be around the coil region. This affects the performance, it seems when it makes this snap that a cylinder did not fire. I checked my wires and am dumbfounded on what could be the issue. I pulled one of my wires and it the snapping rate increased to what seemed like twice as fast.

I am looking for some advice on how to go about troubleshooting this, I have never seen or heard of this so I'm scratching my head on this one. Thanks in advance.


- Jordan

1980 Suzuki Gs 550

[JEEPRUSTY]

Last time I heard that snap was on a coil that had a hairline crack in its housing and was shorting to the frame.
I confirmed this by removing the tank and observing the coils in pitch black conditions.
A nebulous arcing was observable in total darkness that I could not see by light of day.

[posplayr]

Sounds like arching, and yes you are having a spark jump a gap and not go to the plugs. Current follows path of least resistance so either it is a big gap or wire to plugs are bad.

[larson7]

One thing that concerned me was how close the terminals are located to the bolt spacer that fastens the coil(dyna 3 ohm green coils) could it be arcing here? I put electric tape on the terminals just because it seemed far to close for my liking.

Could I try and test this by taking it off the mounting location and starting it up, or does the coil need to be properly grounded on those tabs?

[posplayr]

I pull the tank and watch in the dark where it is arching. Go from there.

[JEEPRUSTY]

Electrical tape is not likely to be sufficient to resist the high voltage that a coil puts out.