from another speed controller from maxx (mx-9208, pdf link at http://www.maxxprod.com/pdf/mx-92...sheet.pdf) the documentation says (the *** where added by me):

SET UP & INSTALLATION:
1. Connect a power pack to MX-9208 and make sure the polarity is correct. Reverse polar-ity
will damage the unit. The battery leads are on the same side as the receiver connector.
2. Connect the MX-9208 to the motor. Keep motor wires and battery wires as short as
possible to reduce weight and resistance.
3. While keeping the throttle stick at idle, turn on your radio system. Then, connect or turn on
the airborne power pack. The BEC will provide power to servos and receiver. **** IMPORTANT **** The throttle
channel is not functional at this moment. **** IMPORTANT ****

*********** This is the important part ***************
4. To activate the throttle channel, quickly move the throttle stick forward and return to idle
within one second. When you forward the throttle stick again, the motor will start running
and respond to the stick movement.
******************************************************

5. Reverse the polarity of the motor, if necessary, to obtain desired rotational direction.
6. Install propeller when rotational direction is correct.
7. Whenever power is disconnected to the unit, your will need to repeat step 4 to reactivate
the unit.

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Reading *4* I can assume that controller is for throttle motor, and your model for a boat (for a propeller). That controller seems like a safety start (or save finger :-). You turn your "boat" on, the servos for direction (the helm, is that the correct word?) start workink and only when you do the start sequence in the remote control the propeller motor starts to run.

Send that sequence (or the appropiate one for your model, I couldn't find any info about it) and things should be ok.

hth

orlando