A variable speed control system and method for a walk-behind working machine includes a control system base, a control lever selectively movable with respect to the control system base between two operating positions, a mode actuator positioned on the control system base for toggling between a plurality of control modes, and a control unit in communication with the control lever, the mode actuator, and a machine component. The control unit selectively controls the operation of the machine component between a minimum operating speed and a variable maximum operating speed. The control unit applies a different acceleration profile to accelerate from the minimum operating speed to the variable maximum operating speed depending on the control mode selected.
