Throttle valve closure sensing switch

In apparatus for adjusting the position to which a carburetor throttle valve closes, the apparatus comprising a reversible d.c. motor having a rotatable shaft, an extendible and retractable member contacting and contacted by a throttle lever which moves the throttle valve, and a set of gears for translating rotary movement of the motor shaft in either direction into linear movement of the member in the appropriate direction, the improvement comprising switch means for sensing when the throttle valve moves towards it substantially closed position, the switch means including a set of electrical contacts each of which is mounted on the end of a spring with one of the springs having a U-shaped segment, means engaging the extendible and retractable member for moving one of the contacts into contact with the other when the throttle lever contacts the member as the throttle valve closes, means biasing the engaging means against the member to preload the member, and means for adjusting the position of the electrical contacts relative to each other.