ORIGINAL: Desertlakesflying
I would never ever run an ignition off my receiver battery. I have 3 batteries in one of mine with a gasser. Smart fly, 2 7.2 lipos for the receiver and servos and a separate 7.2v lipo for the ignition.
It is simply impossible for noise generated in a switching regulator to interfere with a 2.4 ghz spread system. In the first place the generated noise is way to low to get anywhere near 2.4ghz. Then its a spread spectrum system. This system has been developed specifically to reject interference. You have to generate enough noise to wipe out the entire band to prevent the message from getting through. Spend a little time to learn how it works.
I think the answer is in post 15. He had the ailerons hooked up backwards.
BTW I fly small gas models. I use one A123 battery supplying both the receiver and the ignition. I just drop the voltage a bit with diodes for the ignition.