Abstract: An air throttle for an internal combustion engine having a shaft mounted butterfly vane mounted for rotation in the engine charge air inlet. The butterfly vane and shaft have an idle air bleed slot therethrough with a tubular idle valve mounted over said shaft for concentric rotation thereabout. With the butterfly vane closed for idle mode running, the idle valve is rotated between set limits to control idle air flow and idle speed. Upon rotation of the idle valve beyond the set limits, the butterfly is progressively opened for off-idle mode running speed control.