A tiller for an outboard motor has a throttle grip that is manually rotatable through first and second ranges of motion into and between an idle position in which the outboard motor is controlled at an idle speed, and first and second open-throttle positions, respectively, in which the outboard motor is controlled at an above-idle speed. A throttle shaft is coupled to the throttle grip and is configured so that rotation of the throttle grip causes rotation of the throttle shaft, which changes a throttle position of a throttle of the outboard motor. A rotation direction switching mechanism is manually positionable into a first position in which rotation of the throttle grip through the first range of motion controls the throttle of the outboard motor and alternately manually positionable into a second position in which rotation of the throttle grip through the second range of motion controls the throttle position.