Abstract: A carburetor comprising a combined float bowl and venturi section including an air passage with a venturi, a rotatably supported throttle valve plate located in the air passage, and a float chamber adapted to contain fuel, and a separate metering section mounted on the float bowl and venturi section, the metering section being molded of plastic and including a fuel passage communicating between the float chamber and the air passage, a needle valve seat within the fuel passage, an internally threaded bore having therein threads molded integrally with the metering section, and an externally threaded needle valve threadedly received in the bore and being movable into and out of engagement with the valve seat for controlling fuel flow through the fuel passage.

Abstract: A carburetor including a valve apparatus comprising a wall defining a chamber having an axis and having therein an inlet communicating with the chamber and an outlet communicable with the chamber and having a valve seat, a valve member having two opposite ends and a variable length in the direction of the axis which decreases only when at least a predetermined force is applied to the valve member in the direction of the axis, the wall supporting the valve member and being threaded so as to allow movement of the valve member along the axis and into and out of sealing engagement with the valve seat, the wall having a step extending into the chamber and engageable with the valve member, the step limiting the movement of one end of the valve member towards the valve seat.

Abstract: A carburetor comprising a fuel/air induction passage, a secondary orifice communicating with the induction passage, and a fuel supply system operable to supply fuel from a source of fuel to the secondary orifice, the fuel supply system including a wall defining an elongated enclosed chamber having a longitudinal axis and a first end, the wall including an inlet communicating between the source of fuel and the chamber, and, at the second end, an outlet communicating between the chamber and the secondary orifice, the outlet including a valve seat, a valve member within the chamber and including a needle portion adapted to engage the valve seat, the valve member being movable within the chamber along the longitudinal axis of the chamber relative to a closed position wherein the needle portion sealingly engages the valve seat, a spring biasing the valve member toward the closed position, and an adjustment rod selectively engageable with the valve member for selectively and releasably moving the valve member away