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: 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: 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: 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 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: 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: 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: 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: In one form, a carburetor may include an air passage, a fuel and air mixing passage, a throttle valve, an air valve and a lost motion coupler interconnecting the air valve and the throttle valve. The throttle valve may be disposed in communication with the fuel and air mixing passage and moveable between an idle position and an open position permitting an at least somewhat less restricted fluid flow therethrough than when the throttle valve is in the idle position. The air valve may be disposed in communication with the air passage, and moveable between closed and fully open positions to control air flow through the air passage.

Abstract: A control circuit for use with an ignition system of a light-duty combustion engine. In one embodiment, the control circuit includes a charging circuit, a timing circuit and a shut down circuit that includes a manual stop switch. Activation of the manual stop switch causes the control circuit to shut down the engine, and can do so even if the manual stop switch is only momentarily engaged by the operator.

Abstract: A fuel and air charge forming device, such as a carburetor, may include a main body, a fuel and air mixing passage in the body, a fluid passage communicating with the fuel and air mixing passage and a solenoid valve. The solenoid valve may include a coil and a valve body having a base fixed against movement and a valve head extending from the base. The valve head may be driven by the coil between a first position wherein the valve head at least partially obstructs the fluid passage and a second position wherein the valve head permits greater fluid flow in the fluid passage to control fluid flow through the fluid passage.

Abstract: A carburetor valve and limiter cap assembly for limiting adjustment of fuel flow in a carburetor may include a needle valve and a limiter cap. The needle valve may have a tip, a threaded portion, a head having a flange with an outer diameter greater than the rest of the head, and one or more serrations formed on the head. The limiter cap may have a sidewall, a tab extending outwardly from the sidewall, a first cavity having an inner diameter sized for an interference fit with the flange, and at least one driving feature to engage at least one serration so that rotation of the limiter cap causes rotation of the needle valve. The interference fit between the flange and the limiter cap inhibits removal of the limiter cap from the needle valve to prevent undesired adjustment of the needle valves by an end user.

Abstract: An adjustment limiting device for a carburetor including a fuel adjustment valve rotatable to adjust a supply of fuel in or delivered from the carburetor includes an adjustment limiting cap and a connector. The adjustment limiting cap is adapted to be disposed over a portion of the fuel adjustment valve and includes a rotary connection feature adapted to limit relative rotational movement between the adjustment limiting cap and the fuel adjustment valve, and a rotation limiter to limit rotational movement of the adjustment limiting cap. The connector may be carried by the adjustment limiting cap to maintain the adjustment limiting cap on the fuel adjustment valve. The connector may be concealed by the carburetor body, permit the adjustment limiting cap to be fitted onto the fuel adjustment valve, and prevent the adjustment limiting cap from being removed from the fuel adjustment limiting valve.

Abstract: A scavenging valve assembly is used in a carburetor. The valve assembly includes a throttle valve and a rotary air valve. The throttle valve opens and closes an air-fuel passage. The rotary air valve opens and closes an air passage and has one or more air bore(s). When the rotary air valve begins to rotate, airflow travels through the bore(s) and the size of an opening area that airflow travels through continuously increases in size.

Abstract: A method, fuel system, and components for facilitating the delivery of liquid fuel from a fuel tank in fluid communication with a float bowl carburetor of an internal combustion engine, wherein evaporative emissions of the fuel from the fuel tank and float bowl carburetor are mitigated. During operation of the engine, fluid communication is permitted between the fuel tank and the carburetor, and fuel vapors at a predetermined threshold superatmospheric pressure are permitted to vent outwardly from the fuel tank. During inoperation of the engine, fluid communication is prevented between the fuel tank and the carburetor, and fuel vapors at a predetermined threshold superatmospheric pressure are permitted to vent outwardly from the fuel tank.

Abstract: A starting system for a combustion engine including a carburetor with a throttle valve moveable between idle and wide open positions, a throttle control to control movement of the throttle valve during normal operation of the engine, and a linkage between the throttle control and the throttle valve. The starting system includes a recoil pulley, a pull-cord to rotate the recoil pulley, an actuator moveable in response to rotation of the recoil pulley, and a throttle override device. The throttle override device has a first control member moveable from a first position to a second position in response to movement of the actuator, and a second control member moveable in response to movement of the first control member from a first to a second position. The second control member is operably associated with the linkage to prevent the throttle valve from being in its wide open position when the second control member is in its second position.

Abstract: A carburetor includes a main body defining a bore, a main passage and a venturi defined within the bore, and a fuel nozzle carried by the main body and including a fuel nozzle outlet communicating with the venturi. The carburetor may also include a valve member translatable across an axis of the bore, such that in a closed state, the valve member closes the main passage but maintains the venturi at least partially open. The carburetor may also include a needle valve disposed at an end of the fuel nozzle substantially opposite of the fuel nozzle outlet to variably control flow of fuel into a fuel nozzle inlet, and a needle valve transmission may be coupled between a throttle shaft and the needle valve to convert rotation of the throttle shaft to translation of the needle valve.

Abstract: A vapor separator includes a fuel pump, and a container at least partially defining a fuel reservoir to hold fuel and a pump chamber to hold the fuel pump. A closure is carried by the container to close the fuel reservoir and at least partially defines a vapor chamber above a level of fuel in the fuel reservoir and in fluid communication with the pump chamber. A vapor vent device is carried by the closure to allow fuel vapor to vent out of the vapor separator from the vapor chamber and prevent liquid fuel from flowing therethrough when the vapor separator is declined.