Abstract: A carburetor fuel mixture adjustment assembly has a threadable holder which suppresses rotation of a needle valve body disposed within an elongated receptacle defined within a carburetor body. The threadable holder is rigidly engaged within a threading chamber of the receptacle. During assembly, the needle valve body is extended through a bore of the holder as a threading portion of the valve body rotateable cuts an interior threading groove into the threadable holder. The threadable holder is held rigidly within the threading chamber by the carburetor body. A sealing holder is disposed within the receptacle axially inward of the threadable holder and is prevented from rotating within the receptacle by the threadable holder. A stem holder portion of the sealing holder assures a needle portion of the needle valve assembly remains concentrically disposed within an outlet orifice of a fuel chamber of the receptacle.

Abstract: A carburetor fuel mixture adjustment assembly has a threadable holder which suppresses rotation of a needle valve body disposed within an elongated receptacle defined within a carburetor body. The threadable holder is rigidly engaged within a threading chamber of the receptacle. During assembly, the needle valve body is extended through a bore of the holder as a threading portion of the valve body rotateable cuts an interior threading groove into the threadable holder. The threadable holder is held rigidly within the threading chamber by the carburetor body. A sealing holder is disposed within the receptacle axially inward of the threadable holder and is prevented from rotating within the receptacle by the threadable holder. A stem holder portion of the sealing holder assures a needle portion of the needle valve assembly remains concentrically disposed within an outlet orifice of a fuel chamber of the receptacle.

Abstract: A carburetor for an internal combustion engine with an accelerator fuel pump in the carburetor having a piston actuated by a cam on a throttle valve shaft and a ball between them. The axis of a pump chamber in which the piston is slidably received is offset from and eccentric to the axis of rotation of the throttle shaft so that little fuel is supplied to the operating engine by the accelerator pump as the shaft is rotated to move the throttle valve from its idle position to an intermediate position and most of the fuel supplied by the accelerator pump to the engine is delivered as the shaft is rotated to move the throttle valve from the intermediate position to its wide open throttle position.