Abstract: The present invention is concerned with an electronic fuel control system including a carburettor having a throttle bore, a fuel chamber, and at least one fuel circuit extending between the fuel chamber and the throttle bore and controlled by an adjustment member such as a needle, the control system further including an actuator operable to automatically adjust the adjustment member in response to one or more engine operating parameters.

Abstract: The present invention is concerned with an electronic fuel control system including a carburettor having a throttle bore, a fuel chamber, and at least one fuel circuit extending between the fuel chamber and the throttle bore and controlled by an adjustment member such as a needle, the control system further including an actuator operable to automatically adjust the adjustment member in response to one or more engine operating parameters.

Abstract: A carburetor for feeding separate lean and rich channels of an engine intake duct includes a body having a mixing passage with an air intake side and an engine outlet side. A throttle shutter is rotatable about an axis transverse the mixing passage, and a partition is located within the mixing passage upstream of the throttle shutter. The downstream edge of the partition is adjacent the throttle shutter axis whereby in use of the carburetor the partition defines an extension of the lean and rich channels upstream of the throttle shutter, the partition thus providing substantial isolation between the lean and rich channels for all rotational positions of the throttle shutter. In a preferred embodiment a choke shutter is located upstream of the throttle shutter and is rotatable about a further axis transverse the mixing passage, the upstream edge of the partition being adjacent to the axis of the choke shutter.

Abstract: A carburetor 9 for feeding separate lean and rich channels 12, 13 of an engine intake duct 14 comprises a body 20 having a mixing passage 22 with an air intake side 24 and an engine outlet side 26. A throttle shutter 16 is rotatable about an axis transverse the mixing passage, and a partition 10 is located within the mixing passage upstream of the throttle shutter. The downstream edge of the partition 10 is adjacent the throttle shutter axis 16A whereby in use of the carburetor the partition defines an extension of the lean and rich channels upstream of the throttle shutter, the partition thus providing substantial isolation between the lean and rich channels for all rotational positions of the throttle shutter. In a preferred embodiment a choke shutter 17 is located upstream of the throttle shutter and is rotatable about a further axis 17 A transverse the mixing passage, the upstream edge of the partition being adjacent to the axis of the choke shutter.

Abstract: A fuel metering system comprises a throttle body 1 having an air passage 2, a throttle valve 6 mounted in the air passage, and at least one port 9-11, 13 opening into the air passage which is responsive to engine manifold vacuum to provide a negative pressure signal at a connector 12 or 14. The system also includes a repeater (FIG. 2) remote from the throttle body having a fuel inlet, a fuel outlet for delivery of fuel to the engine, and means for metering the delivery of fuel as a function of the negative pressure signal.

Abstract: A carburetor adjustment screw apparatus includes an adjusting screw (2) having a shaft (7) in screw threaded engagement with a carburetor body (4) and a head (8) by which the shaft may be rotated. A generally tubular open-ended housing (10) surrounds the head of the screw and a ring (11) is rotatably mounted in the open end of the housing. Stop means (19/20) limit the angular range of rotation of the ring. A plug (12) is mounted in the ring and engages the screw such that rotation of the plug effects corresponding rotation of the screw. The plug is movable relative to the ring between a first axial position wherein the plug can rotate independently of the ring and a second axial position wherein the plug engages the ring for co-rotation therewith such that the angular range of rotation of the plug is limited to the angular range of rotation of the ring.

Abstract: A fuel adjustment screw apparatus for a diaphragm-type carburetor comprises a screw member (4) having a shaft (4a) and a head (12) by which the shaft may be rotated, with a generally tubular open-ended housing (9) surrounding the head of the screw member. A cap member (10) is mounted in the housing and is movable axially of the screw member between a first position (as seen in FIG. 1) and a second position (FIG. 2). The cap member is held clear of the head of the screw member in the first position so that the screw member can rotate freely, and engages over the head of the screw member in the second position for rotation with the head. The housing has stop means (20) which is engaged by the cap member in the second position for limiting the angle of rotation of the head.