RE: Aerobird motor
If the motor is starting and stopping repeatedly, you probably have an issue with interference or signal loss. Electronic speed controls will shut the motor off when the signal is lost.
Now, one of the possible causes of this issue is the motor. It could be nearing the end of its useful life, and there could be a lot of sparking going on at the brushes. Sparking causes interference, and it could be bad enough that at longer distances where the radio signal is weaker, you get glitches.
Horizon considers the entire fuselage section to be a throw-away item, just like the wing or tail pieces. These planes were designed for people with little or no mechanical ability, and to be as inexpensive as possible, so they're not particularly serviceable. You can, however, replace the motor with a standard 6V Speed 400, because that's exactly what it is.