In at least some implementations, a charge forming device includes a main body, a throttle valve and an adjuster. The main body includes a main bore through which fluid flows for delivery to an engine. The throttle valve is carried by the main body and moveable relative to the main bore to control fluid flow through the main bore. And the adjuster is moveable relative to the throttle valve and engageable with the throttle valve to adjust the range of motion of the throttle valve. In at least some implementations, the adjuster limits the range of motion of the throttle valve when the adjuster is engaged with the throttle valve.

An internal combustion engine kart implementing an accelerator cable connecting an accelerator pedal and an operating lever rotating an air inlet flap controlling the amount of air entering the engine, and a controller receiving at least one control signal emitted by a remote transmitter. The kart includes a movable stop acting on the operating lever so as to change its range of movement and consequently a level of maximum opening of the air inlet flap. The movement of the movable stop depends on the control signal.