Did you use a non-conductive throttle linkage? A conductive throttle linkagehas beenknown to"feed" ignition noise into the throttle servo and back to the receiver. Also, if you are using ganged Aileron servos (i.e. two on each wing): On my 33% Extra 300L, I separated the ganged aileron servos using smartfly's Equalizer II. Theyacted erratically w/o the Equalizer in between the AR9210 receiver and the servos. I could not just use Ys on ganged digital servos.</p>