Abstract: A carburettor includes a primary air passage (19), an adjustable throttle valve (8) situated within the primary air passage, a fuel supply nozzle (28) communicating with the primary air passage and connected to a fuel metering valve for varying the amount of fuel discharged through the nozzle. The fuel metering valve includes an elongate sleeve (32) movably accommodating an elongate valve member (33). The sleeve and valve member define a fuel inlet space (35). A fuel inlet (37) communicates with the fuel inlet space. A fuel outlet (39) passes through the wall of the sleeve (32) and communicates with the fuel supply nozzle (28). A portion of the outer surface of the valve member (33) is so profiled that the valve member (33) is movable relative to the sleeve (32) such that the area of communication between the fuel inlet space (35) and the outlet (39) varies progressively between a maximum and a minimum value.

Abstract: A carburettor including a primary air passage, an adjustable throttle valve situated within the primary air passage, a fuel supply nozzle communicating with the primary air passage and connected to a fuel metering valve for varying the amount of fuel discharged through the nozzle and a rotary input shaft adapted to be connected to an engine speed control member and which is connected to the throttle valve to move the throttle valve between open and closed positions. The rotary input shaft is also connected to a carriage to move the carriage, the carriage carrying at least one elongate inclined ramp which extends in the direction of movement of the carriage and which is engaged by a follower connected to the valve member. Rotation of the input shaft results in movement of the throttle valve and in movement of the carriage and thus of the elongate ramp, wherein the follower is moved transverse to the length of the ramp and the valve member of the fuel metering valve is thus also moved.

Abstract: A carburettor including a primary air passage, an adjustable throttle valve situated within the primary air passage, a fuel supply nozzle communicating with the primary air passage and connected to a fuel metering valve for varying the amount of fuel discharged through the nozzle and a rotary input shaft adapted to be connected to an engine speed control member and which is connected to the throttle valve to move the throttle valve between open and closed positions. The rotary input shaft is also connected to a carriage to move the carriage, the carriage carrying at least one elongate inclined ramp which extends in the direction of movement of the carriage and which is engaged by a follower connected to the valve member. Rotation of the input shaft results in movement of the throttle valve and in movement of the carriage and thus of the elongate ramp, wherein the follower is moved transverse to the length of the ramp and the valve member of the fuel metering valve is thus also moved.

Abstract: A carburettor includes a primary air passage (19), an adjustable throttle valve (8) situated within the primary air passage, a fuel supply nozzle (28) communicating with the primary air passage and connected to a fuel metering valve for varying the amount of fuel discharged through the nozzle. The fuel metering valve comprises an elongate sleeve (32) movably accommodating an elongate valve member (33). The sleeve and valve member define a fuel inlet space (35). A fuel inlet (37) communicates with the fuel inlet space. A fuel outlet (39) passes through the wall of the sleeve (32) and communicates with the fuel supply nozzle (28). A portion of the outer surface of the valve member (33) is so profiled that the valve member (33) is movable relative to the sleeve (32) such that the area of communication between the fuel inlet space (35) and the outlet (39) varies progressively between a maximum and a minimum value.

Abstract: An improved fuel air mixture apparatus which enhances the degree of mixing of fuel with air. The fuel-air mixture device includes a primary air passage having an inlet, an adjustable throttle and an outlet; a secondary air passage having an inlet and an outlet to the primary air passage between its adjustable throttle and its outlet; a nozzle having an orifice opening into the secondary air passage for introducing a flow of fuel therein; a needle arranged co-axially of the nozzle with its small diameter at least normally extending from the orifice into the secondary air passage, the needle being axially moveable to provide variability of the orifice and control of the fuel flow; a control device for directly linking or controlling the position of the needle to the position of the adjustable throttle in the primary air passage for adjustment of the orifice of the nozzle.