Abstract: Inside the fuel tank of a small engine liquid fuel system is a buffer chamber that has its interior communicated with the rest of the tank interior only through a small upper air vent and a restricted bottom fuel port. During fueling, fuel enters the buffer chamber slowly and continues to enter it after the tank is apparently full, lowering the fuel level sufficiently to prevent seepage through the tank cap. The engine crankcase is vented to the carburetor air induction passage through a breather check valve in the carburetor body. A first valve, responsive to pressure differences between the atmosphere and the tank interior, vents overpressures in the tank to the crankcase. A second valve, responsive to the difference between tank pressure and subatmospheric cranckcase pressure, admits air to the tank when the engine is running.

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.