Abstract: A throttle body assembly for a combustion engine includes a throttle body having a pressure chamber including a supply of liquid fuel, and a throttle bore with an inlet through which air is received. A throttle valve is carried by the throttle body with a valve head movable relative to the throttle bore. A metering valve is coupled to the throttle body, and has a valve element that is movable between open and closed positions. A boost venturi is located in the throttle bore and has an inner passage that is open at both ends to the throttle bore. The boost venturi has an opening through which fuel flows into the inner passage when the valve element is in the open position, wherein fuel flows from the pressure chamber to the metering valve under the force of gravity or under a pressure of less than 6 psi.

Abstract: A fuel supply device includes a main body, fuel chamber, fuel supply pipe and a fuel valve. The main body has a main bore with an inlet for air and an outlet through which a fuel and air mixture flows. The fuel chamber retains a supply of fuel. The fuel supply pipe has a passage communicating with the main bore and through which fuel from the fuel chamber flows to the main bore. And the fuel valve has a valve seat, a valve element movable relative to the valve seat between an open position and a closed position, an inlet upstream of the valve seat and is in communication with the fuel chamber, and an outlet downstream of the valve seat. The outlet is coaxially aligned with the passage of the fuel supply pipe and the fuel valve is electrically operated to move the valve element.

Abstract: A throttle body may have a main bore for supplying a fuel and air mixture to an engine. A throttle valve head may be received in the main bore and movable between idle and wide open positions to control fluid flow through the main bore. A main fuel outlet and a boost venturi may open to the main bore and a flow directing feature may alter the velocity and/or direction of fluid flow in the main bore relative to the fuel outlet or boost venturi. The flow directing feature may be carried by the body, the throttle valve head, or the boost venturi.

Abstract: A fuel supply device includes a main body, fuel chamber, fuel supply pipe and a fuel valve. The main body has a main bore with an inlet for air and an outlet through which a fuel and air mixture flows. The fuel chamber retains a supply of fuel. The fuel supply pipe has a passage communicating with the main bore and through which fuel from the fuel chamber flows to the main bore. And the fuel valve has a valve seat, a valve element movable relative to the valve seat between an open position and a closed position, an inlet upstream of the valve seat and is in communication with the fuel chamber, and an outlet downstream of the valve seat. The outlet is coaxially aligned with the passage of the fuel supply pipe and the fuel valve is electrically operated to move the valve element.

Abstract: A throttle body assembly for a combustion engine includes a throttle body having a pressure chamber including a supply of liquid fuel, and a throttle bore with an inlet through which air is received. A throttle valve is carried by the throttle body with a valve head movable relative to the throttle bore. A metering valve is coupled to the throttle body, and has a valve element that is movable between open and closed positions. A boost venturi is located in the throttle bore and has an inner passage that is open at both ends to the throttle bore. The boost venturi has an opening through which fuel flows into the inner passage when the valve element is in the open position, wherein fuel flows from the pressure chamber to the metering valve under the force of gravity or under a pressure of less than 6 psi.

Abstract: A throttle body assembly for a combustion engine includes a throttle body having a pressure chamber including a supply of liquid fuel, and a throttle bore with an inlet through which air is received. A throttle valve is carried by the throttle body with a valve head movable relative to the throttle bore. A metering valve is coupled to the throttle body, and has a valve element that is movable between open and closed positions. A boost venturi is located in the throttle bore and has an inner passage that is open at both ends to the throttle bore. The boost venturi has an opening through which fuel flows into the inner passage when the valve element is in the open position, wherein fuel flows from the pressure chamber to the metering valve under the force of gravity or under a pressure of less than 6 psi.

Abstract: A throttle body may have a main bore for supplying a fuel and air mixture to an engine. A throttle valve head may be received in the main bore and movable between idle and wide open positions to control fluid flow through the main bore. A main fuel outlet and a boost venturi may open to the main bore and a flow directing feature may alter the velocity and/or direction of fluid flow in the main bore relative to the fuel outlet or boost venturi. The flow directing feature may be carried by the body, the throttle valve head, or the boost venturi.

Abstract: A charge forming device includes a housing having an inlet chamber in which a supply of fuel is received, a vent passage communicating with the inlet chamber and a throttle bore with an inlet through which air is received, a throttle valve carried by the housing with a valve head movable relative to the throttle bore to control fluid flow through the throttle bore, a vent valve. The vent valve is carried by the housing and has a valve element that is movable between an open position wherein fluid may flow from the inlet chamber through the vent passage and a closed position where fluid is prevented or inhibited from flowing out of the inlet chamber through the vent passage, the vent valve being electrically actuated, and wherein the vent valve is actuated as a function of a pressure within the inlet chamber or the vent passage.

Abstract: A throttle body may have a main bore for supplying a fuel and air mixture to an engine. A throttle valve head may be received in the main bore and movable between idle and wide open positions to control fluid flow through the main bore. A main fuel outlet and a boost venturi may open to the main bore and a flow directing feature may alter the velocity and/or direction of fluid flow in the main bore relative to the fuel outlet or boost venturi. The flow directing feature may be carried by the body, the throttle valve head, or the boost venturi.

Abstract: A throttle body assembly for a combustion engine includes a throttle body having a pressure chamber including a supply of liquid fuel, and a throttle bore with an inlet through which air is received. A throttle valve is carried by the throttle body with a valve head movable relative to the throttle bore. A metering valve is coupled to the throttle body, and has a valve element that is movable between open and closed positions. A boost venturi is located in the throttle bore and has an inner passage that is open at both ends to the throttle bore. The boost venturi has an opening through which fuel flows into the inner passage when the valve element is in the open position, wherein fuel flows from the pressure chamber to the metering valve under the force of gravity or under a pressure of less than 6 psi.

Abstract: A charge forming device includes a housing having an inlet chamber in which a supply of fuel is received, a vent passage communicating with the inlet chamber and a throttle bore with an inlet through which air is received, a throttle valve carried by the housing with a valve head movable relative to the throttle bore to control fluid flow through the throttle bore, a vent valve. The vent valve is carried by the housing and has a valve element that is movable between an open position wherein fluid may flow from the inlet chamber through the vent passage and a closed position where fluid is prevented or inhibited from flowing out of the inlet chamber through the vent passage, the vent valve being electrically actuated, and wherein the vent valve is actuated as a function of a pressure within the inlet chamber or the vent passage.

Abstract: In at least some implementations, a throttle body assembly for a combustion engine includes a throttle body having a pressure chamber in which a supply of fuel is received and a throttle bore with an inlet through which air is received, a throttle valve carried by the throttle body with a valve head movable relative to the throttle bore to control fluid flow through the throttle bore, and a metering valve carried by the throttle body. The metering valve may have a valve element that is movable between an open position wherein fuel may flow from the pressure chamber into the throttle bore and a closed position where fuel is prevented or substantially prevented from flowing into the throttle bore through the metering valve.

Abstract: In at least some implementations, a charge forming device for a combustion engine includes a housing, a throttle valve and a vent valve. The housing has an inlet chamber in which a supply of fuel is received, a vent passage communicating with the inlet chamber and a throttle bore with an inlet through which air is received. The throttle valve is carried by the housing and has a valve head movable relative to the throttle bore to control fluid flow through the throttle bore. And the vent valve is electrically actuated, carried by the housing and has a valve element that is movable between an open position wherein fluid may flow from the inlet chamber through the vent passage and a closed position where fluid is prevented or inhibited from flowing out of the inlet chamber through the vent passage.

Abstract: In at least some implementations, a throttle body assembly includes a body that has multiple throttle bores, multiple throttle valve heads received one in each of the throttle bores, at least one throttle valve shaft to which the throttle valve heads are coupled, and at least one of a fuel metering valve and a vapor separator carried by the body.

Abstract: In at least some implementations, a charge forming device for a combustion engine includes a housing, a throttle valve and a vent valve. The housing has an inlet chamber in which a supply of fuel is received, a vent passage communicating with the inlet chamber and a throttle bore with an inlet through which air is received. The throttle valve is carried by the housing and has a valve head movable relative to the throttle bore to control fluid flow through the throttle bore. And the vent valve is electrically actuated, carried by the housing and has a valve element that is movable between an open position wherein fluid may flow from the inlet chamber through the vent passage and a closed position where fluid is prevented or inhibited from flowing out of the inlet chamber through the vent passage.

Abstract: In at least some implementations, a throttle body assembly includes a body that has multiple throttle bores, multiple throttle valve heads received one in each of the throttle bores, at least one throttle valve shaft to which the throttle valve heads are coupled, and at least one of a fuel metering valve and a vapor separator carried by the body.

Abstract: A throttle body may have a main bore for supplying a fuel and air mixture to an engine. A throttle valve head may be received in the main bore and movable between idle and wide open positions to control fluid flow through the main bore. A main fuel outlet and a boost venturi may open to the main bore and a flow directing feature may alter the velocity and/or direction of fluid flow in the main bore relative to the fuel outlet or boost venturi. The flow directing feature may be carried by the body, the throttle valve head, or the boost venturi.

Abstract: In at least some implementations, a throttle body assembly for a combustion engine includes a throttle body having a pressure chamber in which a supply of fuel is received and a throttle bore with an inlet through which air is received, a throttle valve carried by the throttle body with a valve head movable relative to the throttle bore to control fluid flow through the throttle bore, and a metering valve carried by the throttle body. The metering valve may have a valve element that is movable between an open position wherein fuel may flow from the pressure chamber into the throttle bore and a closed position where fuel is prevented or substantially prevented from flowing into the throttle bore through the metering valve.

Abstract: A fuel shut-off system for a carburetor substantially reduces or prevents the delivery of fuel to an engine when the engine is turned off and as it coasts to a stop. The fuel shut-off system preferably reduces or eliminates the pressure differential across a nozzle through which fuel is delivered from a fuel chamber through a fuel-and-air mixing passage of the carburetor and into the engine. In this manner, the flow of fuel through the nozzle is reduced and preferably eliminated immediately upon engine turn-off to prevent the after-fire and associated problems within a residually hot exhaust system. The system incorporates an actuator, preferably a solenoid valve, having a first position which obstructs a vacuum bypass passage communicating between the fuel chamber and the fuel-and-air mixing passage, and a second position which enables communication between the vacuum bypass passage and a fuel chamber passage which otherwise communicates with a near atmospheric pressure source.

Abstract: A carburetor has an upper body and a lower separate nozzle post member that extends into the fuel chamber of a lower fuel bowl. The nozzle post member has a main nozzle mixing passage leading from a main fuel jet inlet to a nozzle. An annular air passage and an annular idle fuel passage surround the mixing passage. The nozzle post member also has integrally formed brackets to pivotally mount the fuel float.