Originally Posted by
AA5BY
After exciting the ignition with signal generator, spark breakout was visually noted to be about an inch from the ignition in the HT lead. Opening the shield and inspecting, the center conductor has a horse shoe bend of about 1/8" hump and placing it thus very close to the braided shield where it ruptured through the dialectic.
Who knows why it exist, shrinkage of the dialectic, manufacturing anomaly, or perhaps installation to the ignition error, by soldering the conductor within the ignition and then forcing the dialectic and braided shield into the housing crimp and thus compressing the center conductor causing it to buckle into the horse shoe.
I will try some kind of repair but am unsure of success.
If the spark is outside of the box, it is "repairable", in the sense that the electronics are not shot, and if you find a way to either shorten the existing cable or replace it, it will near 100% sure function again.. Most likely cause is that there was some torque on the HT lead, and if so, it will usually fail at the tightest bend, or so I am told. No personal experience, as I always took great care to route the HT lad in such a way and if necessary rotate the ignition box such that there would be no or minimal torque tension on the lead.
All my ignitions are built in different because of this.
Usually, I coil the lead up one or two turns, or if possible I route the lead rearwards then through the fuselage wall, then back forward to the engine. Routing is done backwards from engine (plug capped) to box, and the way the HT lead wants to turn the box, is how the box will be placed. This method has served me well over the last 9 or so years.