AquaCraft Rio 51Z - Manual (Page 9)

9
3. Squeeze the throttle trigger on the transmitter;
this should open the throat of the carburetor. This is
the proper throttle arm position for full throttle.
4. Idle position.
5. Off or stop position. If this is not the case, move the steering
servo reverse switch located on the front of the transmitter (2) to
the other position. Note: You might have to readjust the position
of the throttle arm on the throttle servo to to match the pictures.