Unplug the motor wires from the motor then perform the procedure for calibrating the ESC throttle positions. Be sure your transmitter settings for CH2 are centered and the end points are set at 100%. Also, I believe with Futaba you need to set that channel to "REVERSE" instead of "NORMAL." You may have to try both the 50/50 and 70/30 neutral positions if it doesn't calibrate correctly.