Topic: 1/4 Coil Blue Wire Crackling?

[Snoefy]

CB500K 1972 had both #1 and #4 not firing. Checked valves and cam chain, assuming compression is good now.

Took the tank off and tested spark, found no spark in both #1 and #4, jiggling the wires around on the coil checking them out I hear a lite but distinct crackling, I believe it’s from the blue wire. Not sure how to proceed or what steps to take.

After juggling the wires to make sure they were on he coils I did get spark back in both #1 and #4

[pjlogue]

Check for arcs from the high tension leads in the dark.  The plug wired may be grounding up by the coil.  A small crack in the insulation or the plastic coil housing can ground out the coil preventing the spark at the plug.

-P.

[bryanj]

The blue wire runs from the coil to a connector in the rubber boot by the rear brake pedal so you can easily run a temporary bypass wire to check for problems.

[Snoefy]

Thank you for the replies - looked like the wire was grounding.