Just a guess,but I agree. Sounds like a capacitor is holding the charge that would normally be delivered to the plug. Cutting power with the kill switch would enable this to happen. While using the throttle to kill eng would drain it. I use both systems in my gas planes but i can't say i've heard it pop. mostly use the kill switch (42%opto kill ) as a safety system in the event of signal loss to receiver, igition switch will kill engine.