This engine is using a 1/4 X 32 spark plug and a walbro WT414 carb. I haven't' checked it out yet, but my radio interference might be caused by the steel table saw I had it sitting on. I was going to crank it in the yard and do a good range check. My ignition is mounted in the nose where the fuel tank usually goes and my AR7000 spektrum RX is in the rear behind the wing which gives me about a foot of separation. The servos were going crazy at about 1/4 to 1/2 throttle then lined out at full throttle.