Abstract: A control system for a small engine operated device includes an emitter carried by the engine or a portion of the device spaced from the engine and a control circuit. The control circuit may include memory with which control data related to device conditions, engine conditions or both is stored, and a processor in electrical communication with the first emitter. The control circuit provides a signal corresponding to the control data to the emitter so that the emitter provides an output in response to device conditions, engine conditions, or both.

Abstract: In at least one implementation a carburetor includes an intake bore with a port opening into the intake bore, a fuel chamber from which fuel is supplied to the intake bore, and an accelerator device including a fuel reservoir. A fuel flow control valve is provided between the fuel chamber and the port to control the flow rate of fuel to the port and at least one passage communicates the fuel reservoir with the port and fuel in the fuel reservoir is supplied to the port therethrough. The passage also communicates the fuel reservoir with the fuel chamber. The fuel flow control valve is located between the fuel reservoir and the port and between the fuel chamber and the port, and the passage includes a portion extending between the fuel reservoir and the fuel chamber independently of the fuel flow control valve.

Abstract: An apparatus for delivering a fuel-air mixture to an engine is provided. The apparatus includes: a carburetor having one or more passages and one or more chambers, wherein at least some of the passages and chambers are in communication with one another, and a fluid pump communicated with the carburetor and pumping fluid into or out of the carburetor to influence an fuel-to-air ratio of a fuel and air mixture delivered from the carburetor.

Abstract: A mount for a level sensor assembly in a fuel tank may include an interconnect member adapted to couple a first tube to a second tube to permit fuel flow through the first tube, the interconnect member and the second tube. The first tube is adapted to be in fluid communication with a fuel pump and the second tube is in fluid communication with fuel in the fuel tank. A bracket is coupled to the interconnect member and adapted to carry at least a portion of the level sensor assembly. In this way, the level sensor assembly may be coupled to fluid tubes associated with the fuel pump, or other tubes, as desired.

Abstract: A purge and prime assembly for a carburetor includes a purge and prime pump that alternately takes in and discharges fluid, and a plurality of passages through which fluid is routed. The passages may include a purge passage through which fluid is drawn by the purge and prime pump, a return passage through which fluid is discharged from the purge and prime pump and discharged from the carburetor, and a priming passage through which a portion of the fluid discharged from the purge and prime pump is routed to a main bore of the carburetor. The assembly may also include a purge valve that prevents fluid from being discharged from the purge prime pump through the purge passage, and a return valve that prevents fluid in the return passage from being drawn into the purge and prime pump.

Abstract: In at least some implementations a carburetor may include a main bore through which a fuel and air mixture is delivered from the carburetor, a fuel metering assembly, a supplemental fuel pump and a valve. The supplemental fuel pump includes a diaphragm that defines a fuel chamber on one side from which fuel may be discharged to at least temporarily increase the amount of fuel discharged from the carburetor and a reference chamber on the other side that is communicated with a reference pressure source. The valve is electrically actuated and moveable between first and second positions to at least substantially prevent communication of the reference pressure source with the supplemental fuel pump diaphragm when the valve is in its second position to thereby inhibit or prevent fuel being discharged from the fuel chamber.

Abstract: In at least some implementations, a carburetor having a fuel metering system including a diaphragm assembly that moves in response to pressure changes in a metering chamber to actuate a metering valve may include a flexible diaphragm adapted to carried by a body of the carburetor at a periphery to define part of the metering chamber. The portion of the diaphragm that defines part of the metering chamber defines a chamber projected area of the diaphragm. A backing plate is attached to the flexible diaphragm and arranged to be located outside the metering chamber. The backing plate having an outer perimeter defining a plate projected area, wherein an area ratio of the plate projected area to the chamber projected area is greater than about 0.1.

Abstract: A method of operating an engine is disclosed, which includes determining a peak power condition for the engine, measuring a temperature associated with the engine at said peak power condition, comparing the temperature measured with a previously determined temperature associated with a known peak power condition of the engine, determining an offset value based on the comparison made in step, controlling at least one of an air-fuel mixture delivered to the engine or ignition spark timing based on said offset value. Various engine fuel delivery systems, carburetors, fuel injection and control systems also are disclosed.

Abstract: In accordance with one implementation, a carburetor includes a body having a fluid passage formed therein and a counterbore located along the fluid passage. The counterbore has a first sealing surface and a central axis, and the body further includes a second sealing surface located radially closer to the central axis than is the first sealing surface. The carburetor also includes a plug affixed to the body at the counterbore and in contact with both of the first and second sealing surfaces. Engagement of the plug with the two sealing surfaces may improve the connection between the plug and carburetor body. In at least some implementations, the plug may be held in place without aid of an adhesive or other secondary connector or connection aid.

Abstract: A fuel pump assembly may include a housing and a fuel pump within a fuel pump cavity. The fuel pump may include a motor, a pumping element driven for rotation by the motor, a pump body that maintains the position of the pumping element relative to the motor and the housing, and a flexible seal. The seal may be disposed between the pump body and the housing to provide a fluid tight seal between them. A portion of the seal may be disposed radially outwardly of a distal end of the pump body to radially position the pump body within the fuel pump cavity and a portion of the seal may be disposed axially outwardly of the distal end of the pump body to axially position the pump body within the fuel pump cavity.

Abstract: A rotary position sensor for determining the rotary position of a rotary component may include a sensor and a magnet. The sensor may be responsive to a characteristic of a magnetic field that changes as the magnetic field moves. The magnet may be carried by the rotary component for rotation with the rotary component and have an anti-rotation feature to prevent rotation of the magnet relative to the rotary component to maintain a desired rotary position of the magnet.

Abstract: In at least one implementation a carburetor includes an intake bore with a port opening into the intake bore, a fuel chamber from which fuel is supplied to the intake bore, and an accelerator device including a fuel reservoir. A fuel flow control valve is provided between the fuel chamber and the port to control the flow rate of fuel to the port and at least one passage communicates the fuel reservoir with the port and fuel in the fuel reservoir is supplied to the port therethrough. The passage also communicates the fuel reservoir with the fuel chamber. The fuel flow control valve is located between the fuel reservoir and the port and between the fuel chamber and the port, and the passage includes a portion extending between the fuel reservoir and the fuel chamber independently of the fuel flow control valve.

Abstract: A fuel and air supply device for an engine includes a carburetor having a fuel metering assembly with a fuel metering diaphragm defining at least part of a reference chamber, a scavenging air assembly including an air passage and an air valve moveable within the passage to alter air flow through the air passage, and a reference passage. The reference passage communicates at one end with the air passage upstream of the air valve and at its other end with the reference chamber to provide a reference air signal through the reference passage to the reference chamber. The reference air signal, in at least some implementations, is taken from a location downstream of an air filter and any other components so it is representative of the air flow at the air valve and accounts for restrictions to air flow caused upstream of the air valve.

Abstract: A fuel pump for a fuel system includes a nozzle, a venturi, a pump inlet and a flow controller. The nozzle has an orifice through which fuel is ejected and the venturi is downstream of the nozzle and has an inlet through which fuel discharged from the orifice flows, a passage downstream of the venturi inlet through which fuel flows to create a drop in pressure in the area of the venturi, and an outlet through which fuel is discharged from the venturi. Fuel is drawn through the pump inlet fuel by the drop in the pressure created in the area of the venturi and the flow controller is downstream of the outlet and has a chamber in which fuel from the venturi outlet is received. The flow controller causes fuel to fill the venturi to ensure performance of the fuel pump.

Abstract: Supply of supplementary fuel is controlled through a supplementary fuel supply passage in a carburetor to an engine according to a variety of methods and devices.

Abstract: In accordance with one implementation, a carburetor includes a body having a fluid passage formed therein and a counterbore located along the fluid passage. The counterbore has a first sealing surface and a central axis, and the body further includes a second sealing surface located radially closer to the central axis than is the first sealing surface. The carburetor also includes a plug affixed to the body at the counterbore and in contact with both of the first and second sealing surfaces. Engagement of the plug with the two sealing surfaces may improve the connection between the plug and carburetor body. In at least some implementations, the plug may be held in place without aid of an adhesive or other secondary connector or connection aid.

Abstract: Supply of supplementary fuel is controlled by activation of a valve in response to certain engine operating conditions or parameters. For example, the supplementary fuel may be supplied to facilitate starting and warming up a cold engine, or to cool and/or slow down an engine operating above a threshold speed.

Abstract: An on-board fuel filter for a carburetor includes a filter element made from a non-metallic material. The material can be a polymeric material and may be a woven or a non-woven material. The fuel filter may be adapted to have an interference fit with a fuel passage of the carburetor and constructed so that the fuel filter is substantially not plastically deformed by the interference fit. Filter elements may be cut from a sheet of polymeric material and aligned with a fuel passage opening in a body of the carburetor while being cut.

Abstract: In at least some implementations, a carburetor having a fuel metering system including a diaphragm assembly that moves in response to pressure changes in a metering chamber to actuate a metering valve may include a flexible diaphragm adapted to carried by a body of the carburetor at a periphery to define part of the metering chamber. The portion of the diaphragm that defines part of the metering chamber defines a chamber projected area of the diaphragm. A backing plate is attached to the flexible diaphragm and arranged to be located outside the metering chamber. The backing plate having an outer perimeter defining a plate projected area, wherein an area ratio of the plate projected area to the chamber projected area is greater than about 0.1.

Abstract: In at least some implementations a carburetor may include a main bore through which a fuel and air mixture is delivered from the carburetor, a fuel metering assembly, a supplemental fuel pump and a valve. The supplemental fuel pump includes a diaphragm that defines a fuel chamber on one side from which fuel may be discharged to at least temporarily increase the amount of fuel discharged from the carburetor and a reference chamber on the other side that is communicated with a reference pressure source. The valve is electrically actuated and moveable between first and second positions to at least substantially prevent communication of the reference pressure source with the supplemental fuel pump diaphragm when the valve is in its second position to thereby inhibit or prevent fuel being discharged from the fuel chamber.