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.

A flap device for an internal combustion engine which includes a flow housing with a housing wall which delimits a flow-through duct. The flap device includes a shaft mounted in the flow housing, a flap body rotatably mounted on the shaft, an actuator for the shaft, and a pressure measurement point. The pressure measurement point is arranged in a duct section of the flow housing so that the flap body traverses the pressure measurement point when rotating, and in a region of the flow housing remote from the shaft when viewed in a circumferential direction of the housing wall. A flap surface of the flap body is directed towards the pressure measurement point and is curved so that, in each rotary position, a tangent arranged at the position of the curved flap surface having a shortest distance to an opposite wall surface of the flow housing is parallel thereto.

A flap device for an internal combustion engine which includes a flow housing with a housing wall which delimits a flow-through duct. The flap device includes a shaft mounted in the flow housing, a flap body rotatably mounted on the shaft, an actuator for the shaft, and a pressure measurement point. The pressure measurement point is arranged in a duct section of the flow housing so that the flap body traverses the pressure measurement point when rotating, and in a region of the flow housing remote from the shaft when viewed in a circumferential direction of the housing wall. A flap surface of the flap body is directed towards the pressure measurement point and is curved so that, in each rotary position, a tangent arranged at the position of the curved flap surface having a shortest distance to an opposite wall surface of the flow housing is parallel thereto.

A rotary throttle valve carburetor includes a main body, a throttle valve and a fuel nozzle. The main body has a main bore with an inlet and an outlet, a valve bore that intersects the main bore and a nozzle opening that communicates with the main bore. The throttle valve has a body received at least partially within the valve bore so that the valve body rotates about an axis and moves axially relative to the main body, and a valve passage therethrough. The fuel nozzle extends through the nozzle opening and into the valve passage, and has a fuel outlet received within the valve passage, an inner surface that defines part of a fuel passage through which fuel flows in the nozzle and to the fuel outlet, and an outer surface that includes a discontinuous portion with a varying radial dimension.

An improved rotary type carburetor for a stratified scavenging engine designed to enable the easy adjustment of air and fuel flow at the time of initial configuration is disclosed. The improved rotary carburetor includes an air intake passage and an air-fuel mixture passage formed in a horizontal direction on a carburetor main body. The throttle valve of the improved rotary carburetor can be fitted into a cylindrical-throttle-valve hole formed orthogonal to a fuel and an air passage of the carburetor main body. The throttle valve has the air supply side valve hole formed on the air intake passage side and a fuel supply side valve hole formed on the air-fuel mixture passage side.

An improved rotary type carburetor for a stratified scavenging engine designed to enable the easy adjustment of air and fuel flow at the time of initial configuration is disclosed. The improved rotary carburetor includes an air intake passage and an air-fuel mixture passage formed in a horizontal direction on a carburetor main body. The throttle valve of the improved rotary carburetor can be fitted into a cylindrical-throttle-valve hole formed orthogonal to a fuel and an air passage of the carburetor main body. The throttle valve has the air supply side valve hole formed on the air intake passage side and a fuel supply side valve hole formed on the air-fuel mixture passage side.

A charge forming device includes a body with a main bore through which air flows and a fuel inlet through which fuel enters the main bore. A diaphragm defines part of a fuel chamber that leads to a fuel passage. The valve body is received in the fuel passage and has a first end, a second end, a sidewall, a valve passage having an inlet into which fuel from the fuel chamber enters and an outlet from which fuel exits for delivery to the main bore, and a cross passage extending through the sidewall between the first end and the second end and opening into the valve passage. A valve is carried by the body and has a valve head received in the cross passage and extending into the valve passage to at least partially inhibit fuel flow through the valve passage.

A carburetor fuel flow control device having an elongate annular body received in a cavity with an inlet in its side-wall communicating with a fuel supply passage and an outlet downstream of the inlet and adjacent to an end of the body, and a needle valve with a metering portion adjacent one end rotatably and slidably received in the body with the metering portion at least partially lapping or blocking the inlet to change the effective flow area of the inlet in response to generally axial movement of the needle valve relative to the inlet.

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.

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.