Hi Ihave a P-51micro mustang from Parkzone.It used to work fine for up to 10 min.Now it starts pulsing the motor at 10 seconds of full throttle and stops the motor at around 1 minute.At half throttle it last 3min 30 sec untill pulsing starts but last over 6min with out stopping the motor.The batteries im using are brand new and fully charged hobbycity flightmax 138Mah.What would make my poor little plane do this? Is the ESCbroken? Is the motor bad? Please help!