Abstract: A fuel delivery system for a combustion engine has a fuel tank which defines an access hole preferably communicating through either the top wall or bottom wall of the tank. An associated top or bottom flange, both having a fuel channel for flowing fuel out of the tank, sealably covers the access hole. A fuel pump module is located in the fuel chamber of the tank and has a universal, structural, pod which engages either the top or bottom flange while preferably maintaining an axial upright position. The pod defines an axially extending first bore for housing a fuel pump and preferably an electric pump motor and a second bore defined by a cylindrical inner face and spaced radially outward from the first chamber for housing a reversible filter cartridge of the module. The pod also has a fuel discharge nozzle which generally defines a counter bore that communicates axially with the second bore.

Abstract: A fuel mixing device includes a fuel passage adapted to communicate fuel from at least one of a first fuel source or a second fuel source provided at a higher pressure than the first fuel with at least one of a first fuel path or a second fuel path. The device also includes a control valve permitting fuel flow through the second fuel path and out of the device when the first fuel is provided in the fuel passage so that the first fuel flows out of the device through both the first and second fuel paths, and the valve prevents fuel flow through the second fuel path and out of the device when the second fuel is provided in the fuel passage so that the second fuel flows out of the device only through the first fuel path.

Abstract: A carburetor includes a fuel and air mixing passage with a throttle valve therein, and a bore with a valve therein defining in part a valve actuation chamber and a separate fuel and air mixing chamber in communication with the fuel and air mixing passage at a location downstream of the throttle valve. A fuel passage and an air passage are in communication with the fuel and air mixing chamber. A purge apparatus is in communication with the valve actuation chamber and is operable to move the valve to an open position to open the fuel and air passages to the fuel and air mixing chamber such that a fuel and air mixture may flow from the fuel and air mixing chamber to the fuel and air mixing passage downstream of the throttle valve.

Abstract: A carburetor includes a body, a fuel metering system carried by the body to regulate fuel flow to the body, and a fuel-and-air mixing passage in fluid communication with the fuel metering system. The mixing passage extends through the body and is partitioned into a rich mixture passage, and a lean mixture passage positioned between the rich mixture passage and the fuel metering system.

Abstract: Methods and fuel systems to reduce evaporative emissions of a volatile fuel. A fuel tank contains fuel, a carburetor mixes air with the fuel from the fuel tank, and a plurality of fluid paths route fuel amongst and/or between the fuel tank and the carburetor. A valve actuation device stops flow of fuel in one or more of the plurality of fluid paths and the carburetor is adapted to be drained of fuel during engine shutdown to reduce or prevent evaporative emissions from the fuel system. The carburetor is preferably designed so as to minimize a volume of fuel contained therein.

Abstract: A control system for a low cost, light duty combustion engine, where the control system generally utilizes an engine speed input signal and independent operating sequences to determine a desired ignition timing. There are several independent operating sequences, each one of which is designed to optimally control the engine under certain conditions. These operating sequences include a Cranking sequence, a Warm Up sequence, a Normal Mode sequence, an Acceleration sequence, a Come Down sequence, a Recovery Bump sequence, and a Part Throttle sequence. During idling conditions, the Normal Mode sequence uses rapid changes in the ignition timing to maintain the engine speed in a small, idle engine speed range. By utilizing these operational sequences, the control system improves the performance of a low cost, light duty engine across a wide array of conditions.

Abstract: A charge forming device may include a body having a fuel and air mixing passage, a throttle valve and choke valve moveable between first and second positions to control at least in part the fluid flow in the fuel and air mixing passage, and throttle and choke control members associated with the throttle and choke valves, respectively. The choke control member may also be associated with an engine starting system so that the choke valve is moved to its second position upon actuation of the starting system. The choke control member is selectively associated with the throttle control member to hold the choke control member in a position spaced from its first position. In this manner, the throttle valve and choke valve may be automatically positioned in a desired position for starting of the engine upon actuation of the engine starting system.

Abstract: A fuel mixing device includes a body having an intake bore, a first surface, and a second surface adjacent to the first surface. A first valve device may be carried by the body on the first surface and a second valve device may be carried by the body on the second surface. A first fuel passage may be provided in the body communicating with the first valve device and adapted to communicate with a supply of fuel. A second fuel passage communicates with the second valve device and the first fuel passage to permit fuel that has passed through the first valve device to flow to the second valve device, wherein the first fuel passage and the second fuel passage connect to at least one of the first surface or the second surface.

Abstract: A scavenging carburetor having an improved relationship between scavenging air flow and fuel-and-air flow to an engine over its range of operating conditions. The carburetor has a butterfly throttle valve and a plug-type scavenging valve. Levers are attached to support shafts of the valves and are connected to each other by a connecting rod so as to synchronize movement of the valves. Because of the different opening angle versus open area properties of the two valves, the supply of the scavenging air is minimized over a low speed range of the engine so as to achieve a stable low speed operation and a stable acceleration from idle conditions and a relatively large amount of scavenging air is supplied over a high speed range of the engine for the given amount of fuel-and-air mixture that is supplied. Therefore, the fuel-and-air mixture supply and scavenging air supply is better matched to the requirements of a particular engine than was possible with conventional combinations of valves.

Abstract: A combustion engine carburetor has a control valve assembly that generally controls flow through a fuel-and-air mixing passage extending through a body of the carburetor. The control valve assembly has at least one valve preferably of a butterfly-type having a shaft that extends transversely across the fuel-and-air mixing passage and journaled for rotation in the body about a rotation axis. The shaft has opposite trailing and leading end portions that project from generally opposing sides of the carburetor body. Axial movement of the shaft with respect to the body is limited by an axial retention feature that preferably has a radially enlarged end cap formed unitarily to the trailing end portion and a coupler snap fitted to the leading end portion.

Abstract: Methods and fuel systems to reduce evaporative emissions of a volatile fuel. A fuel tank contains fuel, a carburetor mixes air with the fuel from the fuel tank, and a plurality of fluid paths route fuel amongst and/or between the fuel tank and the carburetor. A valve actuation device stops flow of fuel in one or more of the plurality of fluid paths and the carburetor is adapted to be drained of fuel during engine shutdown to reduce or prevent evaporative emissions from the fuel system. The carburetor is preferably designed so as to minimize a volume of fuel contained therein.

Abstract: According to one implementation, carburetor includes an intake bore, a throttle valve, a main fuel nozzle, an accelerator device and a fuel passage. The throttle valve is movable between an idle and wide open positions and includes a shaft rotatably supported around an axial line extending across the intake bore. The accelerator device may be operable to increase an amount of fuel that flows through the main fuel nozzle when the throttle valve is moved toward its wide open position, and may include a fuel reservoir constructed and arranged to store fuel. The fuel passage communicates with the main fuel nozzle and the fuel reservoir is provided upstream of the main fuel nozzle such that fuel flows through the fuel reservoir before being delivered to the main fuel nozzle.

Abstract: A capacitive discharge ignition (CDI) system that can be used with a variety of light-duty internal combustion engines, including those typically employed by lawn, garden, and other outdoor equipment. According to one embodiment, the CDI system includes an ignition module having a first switching device that shorts a charge coil during an initial portion of a charge cycle. Subsequently, the first switching device is turned ‘off’ so that a flyback charging technique charges an ignition capacitor. A second switching device is then used to discharge the ignition capacitor and initiate the combustion process.

Abstract: A fuel system for a carburetor that supports operation of an engine includes a body with a bore, a fuel source communicated with the bore and from which fuel is supplied to the bore for delivery to the engine, a drain unit and a control. The drain unit is communicated with the fuel source to selectively receive fuel from the fuel source and has a fuel chamber and an actuator operable to vary the volume of the fuel chamber. The control is communicated with the actuator to permit fuel flow from the fuel source to the fuel chamber when the engine is shut down and to cause fuel to flow from the fuel chamber to the fuel source prior to starting the engine.

Abstract: A fuel control device for a combustion engine capable of running on any one of a plurality of fuels has a fuel selection module with a plurality of fuel type settings for selecting a specific fuel type whereupon the fuel control device controls the outlet pressure of the chosen fuel to a desired fuel pressure corresponding to the calorific properties of the chosen fuel. The fuel selection module preferably operates a plurality of fuel flow circuits each designated for a specific fuel type, and each having a biased closed inlet valve and a biased closed outlet valve. Located preferably between each inlet and outlet valve is a pressure regulator designated for the specific fuel type and controlling the outlet fuel pressure. The device preferably includes a fuel metering apparatus and a shutoff valve that communicate with, and control in part, fuel flow through the fuel flow circuits.

Abstract: A charge forming device includes a body with a fuel and air mixing passage, a bypass passage that communicates with the fuel and air mixing passage, a throttle valve and a choke valve. The throttle valve is movable between idle and wide open positions and operable to control at least in part the fluid flow through the fuel and air mixing passage. The choke valve is movable between an open position permitting a substantially free flow of air into the fuel and air mixing passage and a closed position at least substantially restricting air flow into the fuel and air mixing passage. A bypass valve is movable between an open position and a closed position to selectively permit fluid flow through the bypass passage. The bypass valve is movable toward its open position when the throttle valve is displaced at least a threshold amount away from its idle position.

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 diaphragm carburetor for an internal combustion engine and method of assembly includes attaching an air-fuel mixing body to a fuel metering chamber assembly independent from assembling the fuel metering chamber assembly. The fuel metering chamber assembly has an upper body and a lower body attached to one another by at least one fastener with a diaphragm carried therebetween. A fuel metering chamber is defined on one side of the diaphragm and an atmospheric chamber is defined on another side of the diaphragm. Another fastener attaches the fuel metering chamber assembly to the air-fuel mixing body independently from the fastener attaching the upper and lower bodies together. Accordingly, the fuel metering chamber assembly is removable from the air-fuel mixing body without removing the fastener attaching the upper and lower bodies to one another preferably for cleaning of a fuel nozzle that when assembled projects into an air-fuel mixing passage in the mixing body.

Abstract: A system for reducing escape to the atmosphere of hydrocarbon fuel vapors from a fuel tank for a combustion engine powered device including at least one functional member that directly communicates with the fuel tank and is constructed to receive and retain hydrocarbon vapors therein. The functional member may further include a bed of activated carbon-based material for adsorbing and purging of the hydrocarbon vapors. The functional member is otherwise useful to the device beyond the vapor handling function and may be incorporated into a handlebar assembly, frame component, housing, cover, and the like thereby reducing component parts and reducing cost and complexity of the device.

Abstract: A pull-cord start system has a recoil pulley coupled to a crankshaft of a combustion engine and a pull-cord wound about the recoil pulley which is pulled by an end user to rotate the recoil pulley and thereby start the engine. A throttle override device of the pull-cord start system has a shuttle coupled to the pull-cord for movement from a biased rest position to an active position when the pull-cord is being pulled by an end user. A linkage of the throttle override device which is preferably a Bowden cable extends between a throttle control and a throttle valve of a carburetor and is associated with the shuttle so that actuation of the throttle control when the shuttle is in the active position will not open the throttle valve which preferably is biased to an idle position because movement of the shuttle to the active position produces slack in the linkage.