Abstract: The air vane governor has improved speed droop characteristics under no load and light load conditions to prevent engine stumbling. The air vane governor includes a primary spring and a secondary spring; both springs oppose the movement of the air vane at no load and light load conditions. At increased load, the secondary spring drops out. The tension on both springs is adjustable. The added spring force of the secondary spring makes the governor less sensitive at no load and light load, resulting in more even operation, particularly during engine warmup.

Abstract: A combined float bowl carburetor and fuel pump for small engines has a lateral extension on its carburetor body that terminates at a flat exterior surface to which open certain cavities and a passageway leading to the float valve inlet. A block-like pump body having flat inner and outer surfaces overlies said exterior surface and has cavities opening to its inner surface that cooperate with those in the carburetor body. A resilient pump membrane, providing a pump diaphragm and valves, is confined between the pump body and said exterior surface. Two cavities open to the outer face of the pump body, which is overlain by an imperforate resilient membrane to define inlet and outlet surge chambers that are respectively communicated with the pump by way of the inlet and outlet valves. All cavities, inlets and outlets are arranged to ensure maintenance of a consistent head of fuel at every inlet.

Abstract: End portions of the choke valve shaft project outside the carburetor mixing passage duct. One end portion is connected with an actuator mechanism that is responsive to either engine speed or manifold pressure. The other projects into a cylindrical chamber on the carburetor body that houses a spirally coiled bimetal strip having its inner end connected with the shaft, its outer end engageable with circumferentially spaced abutments. The chamber is communicated with the crankcase breather and also with the mixing duct through a flapper valve, so that the bimetal is subjected to the temperature of vented crankcase vapors.

Abstract: The choke valve of a small engine, biased towards a closed position, is link connected with an air vane that tends to open it under force of cooling air blown across the engine. The air vane has a lost motion connection with a control shaft that is rotatable between defined hot and cold positions. Shaft position is established by two spirally coiled bi-metal thermostats, one for high temperatures, one for low temperatures, each in a unidirectional torque transmitting connection between the shaft and fixed structure whereby each thermostat imposes force upon the shaft only at temperatures within its own range.