Abstract: 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.

Abstract: In at least some implementations, a charge forming system for a combustion engine includes a first fuel supply device having a first passage from which fuel is discharged for delivery to the engine and a second fuel supply device having a second passage from which fuel is discharged for delivery to the engine. The first passage communicates with the second passage so that the fuel in the first passage is combined with the fuel in the second passage.

Abstract: In at least some implementations, a charge forming system for a combustion engine includes a first fuel supply device having a first passage from which fuel is discharged for delivery to the engine and a second fuel supply device having a second passage from which fuel is discharged for delivery to the engine. The first passage communicates with the second passage so that the fuel in the first passage is combined with the fuel in the second passage.

Abstract: 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.

Abstract: In at least some implementations, a carburetor includes a main bore and a valve bore that has a bottom wall, and a throttle valve is received within the valve bore for rotation and axial movement between an idle position and a wide-open position. A first chamber is defined in the valve bore between the bottom wall and the throttle valve, and a second chamber is defined at least partially in the valve bore between the throttle valve and the throttle valve plate. A first passage communicates with the first chamber to permit fluid flow into or out of the first chamber, and a second passage communicates with the second chamber to permit fluid flow into or out of the second chamber. Various implementations may use any combination of inlet passages to the first and/or second chamber, and outlet passages from the first and/or second chamber.