Abstract: A fuel metering pump assembly for delivering fuel to a combustion chamber of an internal combustion engine has a crankcase, a throttle and at least one cylinder. A housing has a fuel inlet and a fuel outlet, and a metering arrangement is disposed in the housing between the fuel inlet and the fuel outlet. The metering arrangement has a plunger rod movable in a chamber between the fuel inlet and the fuel outlet to control the flow of fuel therefrom, and a movable camshaft is engageable with the plunger rod to selectively deliver fuel from the fuel outlet at a predetermined pressure and volume in response to pulses from the crankcase. A motive device is mounted on the housing in direct engagement with the camshaft. The motive device is responsive to the position of the throttle to move the camshaft relative to the plunger rod so as to vary the fuel delivered from the fuel inlet to the fuel outlet.

Abstract: An idle speed control for an internal combustion engine has a crankcase adapted to be connected to a fuel metering device used to selectively deliver fuel to the engine in response to pressurized air pulses generated in the engine. The idle speed control includes a vessel having a pressure actuated member movably mounted therein to define a first chamber and a second chamber. The second chamber is provided with a biasing device acting on one side of the pressure actuated member and the first chamber admits the pressurized air pulses acting on an opposite side of the pressure actuated member and controllably leaking a portion of the pulses therefrom. The idle speed is controlled by a leak-down rate of pressurized air pulses released from the second chamber.