Abstract: A sensor tube structure includes a sensor housing, a sensor mounted on the sensor housing, an external tube mounted at an end of the sensor housing to enclose the sensor, an inner tube provided to be movable inside the external tube, a drive plate in which a sensor hole into which the sensor is inserted is formed, and is coupled to the inner tube, and an actuator mounted on the sensor housing and selectively moving the drive plate.

Abstract: A carburetor with a starting fuel supply mechanism which additionally supplies a starting fuel at the start of an engine includes a choke valve in suction passages extending through a main body; and a starting fuel supply path disposed as a bypass of a main fuel passage to connect a float chamber to the suction passages, the starting fuel supply path being provided with an opening/closing valve opened by interlocking with the closing operation of the choke valve, and a valve body of the choke valve which performs the closing operation presses valve opening/closing device while abutting on one end of the valve opening/closing device, to open the opening/closing valve of the starting fuel supply path, so that the starting fuel can be prepared to be supplied.

Abstract: A carburetor has an air intake passage, a fuel passage, a fuel nozzle in communication with the fuel passage and having an opening through which fuel flows, a first valve in communication with the air intake passage and being movable between first and second positions, and a second valve in communication with the fuel nozzle and also being movable between first and second positions to vary the effective flow area of the fuel nozzle. The fuel nozzle is preferably carried by a tube fitted sealably in a bore being in communication with the fuel passage. The opening is defined by the tube and is preferably elongated, extending axially with respect to the tube. A needle of the second valve moves axially within the tube to variably obstruct the opening to control fuel flow. Preferably, a method of manufacturing the tube utilizes a circular cutting tool which plunges into the tube cutting a slit as the opening having a sharp peripheral edge for atomizing the fuel.

Abstract: A flow rate control mechanism is provided to a low-speed fuel system that is independent from the main fuel system of a carburetor. The mechanism causes the valve element to move in a linear fashion by means of a cam coupled to the throttle stem. The mechanism increases the effective cross-sectional area of the low-speed fuel channel as the throttle valve opens from the idle position to the maximum degree of opening until the point in time at which the main fuel begins to flow, and thereafter causes the low-speed fuel flow rate to decrease and become zero in the high-output region. The transition from low-speed fuel to main fuel is made smooth, ensuring higher output and a stable fuel flow rate in the high-output region.

Abstract: The present invention facilitates the stabilization of the fuel flow rate in a single fuel system carburetor in which bleed air, mixed with fuel, is controlled by a metering needle moving in response to the movement of a throttle valve and the mixture is discharged into an intake channel. The present invention is directed to a carburetor in which an effective surface area of a metering hole is adjusted by a metering needle moving in response to the movement of a throttle valve, and the fuel introduced into a mixing chamber from a constant-fuel chamber under flow rate control with a metering hole is mixed with bleed air and discharged into an intake channel from a nozzle orifice. The mixing chamber has a volume providing for absorption and relaxation of changes in the negative pressure acting upon the nozzle orifice, the fuel is sucked in under stabilized negative pressure, and the air-fuel mixture with a preset air/fuel ratio is supplied over the entire operation range of the engine.

Abstract: In a fuel-air mixture device, downstream of a throttle (4) and a fuel introduction device, a block (51) is provided across the primary air passage (2). The block has a plurality of passageways (54) through it for air flow towards an inlet manifold. These improve mixture of the fuel and air.

Abstract: The present invention facilitates the stabilization of the fuel flow rate in a single fuel system carburetor in which bleed air, mixed with fuel, is controlled by a metering needle moving in response to the movement of a throttle valve and the mixture is discharged into an intake channel. The present invention is directed to a carburetor in which an effective surface area of a metering hole is adjusted by a metering needle moving in response to the movement of a throttle valve, and the fuel introduced into a mixing chamber from a constant-fuel chamber under flow rate control with a metering hole is mixed with bleed air and discharged into an intake channel from a nozzle orifice. The mixing chamber has a volume providing for absorption and relaxation of changes in the negative pressure acting upon the nozzle orifice, the fuel is sucked in under stabilized negative pressure, and the air-fuel mixture with a preset air/fuel ratio is supplied over the entire operation range of the engine.

Abstract: The present invention facilitates the stabilization of the fuel flow rate in a single fuel system carburetor in which bleed air, mixed with fuel, is controlled by a metering needle moving in response to the movement of a throttle valve and the mixture is discharged into an intake channel. The present invention is directed to a carburetor in which an effective surface area of a metering hole is adjusted by a metering needle moving in response to the movement of a throttle valve, and the fuel introduced into a mixing chamber from a constant-fuel chamber under flow rate control with a metering hole is mixed with bleed air and discharged into an intake channel from a nozzle orifice. The mixing chamber has a volume providing for absorption and relaxation of changes in the negative pressure acting upon the nozzle orifice, the fuel is sucked in under stabilized negative pressure, and the air-fuel mixture with a preset air/fuel ratio is supplied over the entire operation range of the engine.

Abstract: A simplified, easy-to-get-at carburetor interference needle adjustment mechanism to cause a carburetor needle to penetrate the carbureting chamber to a greater or lesser extent to achieve improved carburetion at the level of operation desired.