sounds like you may have lost radio calibration. If when you plug in a battery (with the radio on) hold the "on" button down until it lights up (red I think) and then let go. it will start to blink. pull full throttle until it blinks twice, then move the throttle to full reverse, then when it blinks again let go of the throttle, return to neutral. then the light should blink and you might be good to go.

This is from memory, if you r manual has different "throttle calibration" directions, follow those


Tim