Abstract: The design and construction of present engines have generally not compensated for white smoke during start up and cold operating conditions where incomplete combustion occurs. The present invention overcomes these problems by using a control system adapted to be used with the engine and positioned between a restrictor valve and a throttle. The restrictor valve restricts the flow of one of the intake air and the exhaust. A mechanical linkage is connected between the throttle and the valve. The linkage moves a shaft and a plate relative to the throttle high idle position and low idle position respectively. A first lever has a slot therein and is rotatably attached to the shaft and a second lever is fixedly attached to the shaft and has a pin being generally positioned in the center of the slot. The slot allows the first lever to move slightly in either direction relative to the position of the second lever without varying the position of the plate between the generally closed position and the opened position.