Abstract: An engine system may include a fuel and air supply circuit and an exhaust circuit, a temperature sensor mounted on an exterior of the engine and an oxygen sensor located in the exhaust circuit. The fuel and air supply circuit may include a throttle body mounted on the engine and having a throttle valve to control the flow rate of air delivered to the engine, a fuel injector carried by the throttle body to deliver fuel to the engine and a fuel rail carried by at least one of the throttle body and the fuel injector and having an input to receive a supply of fuel and an outlet through which fuel is routed to the fuel injector. An engine control unit may be communicated with these components to control the fuel and air mixture provided to the engine as a function of the temperature and oxygen sensor outputs.

Abstract: An engine system may include a fuel and air supply circuit and an exhaust circuit, a temperature sensor mounted on an exterior of the engine and an oxygen sensor located in the exhaust circuit. The fuel and air supply circuit may include a throttle body mounted on the engine and having a throttle valve to control the flow rate of air delivered to the engine, a fuel injector carried by the throttle body to deliver fuel to the engine and a fuel rail carried by at least one of the throttle body and the fuel injector and having an input to receive a supply of fuel and an outlet through which fuel is routed to the fuel injector. An engine control unit may be communicated with these components to control the fuel and air mixture provided to the engine as a function of the temperature and oxygen sensor outputs.

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 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: 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. A buffer may be provided around the magnet to limit distortion of the magnet field. The buffer is effective against objects normally located in the area of a device with which the sensor is used (e.g. adjacent components) as well as against foreign objects not normally in the area of the device.

Abstract: An engine system may include a fuel and air supply circuit and an exhaust circuit, a temperature sensor mounted on an exterior of the engine and an oxygen sensor located in the exhaust circuit. The fuel and air supply circuit may include a throttle body mounted on the engine and having a throttle valve to control the flow rate of air delivered to the engine, a fuel injector carried by the throttle body to deliver fuel to the engine and a fuel rail carried by at least one of the throttle body and the fuel injector and having an input to receive a supply of fuel and an outlet through which fuel is routed to the fuel injector. An engine control unit may be communicated with these components to control the fuel and air mixture provided to the engine as a function of the temperature and oxygen sensor outputs.

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 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 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: A fuel metering system for a combustion engine carburetor utilizes a non-convoluted, planar, flexible diaphragm which does not require a molding process to form a traditional convolution. The diaphragm defines in part a pressure controlled fuel metering chamber on one side and a reference chamber at atmospheric pressure on the other side. During operation of the engine, sub-atmospheric pressure within a fuel and air mixing passage draws fuel from the metering chamber to mix with air for combustion within the engine. As pressure within the metering chamber thus decreases, the diaphragm flexes into metering chamber. The displacement of the diaphragm actuates a flow control valve of the metering system which flows pressurized make-up fuel into the metering chamber until the diaphragm returns to its datum position.

Abstract: A fuel metering system for a combustion engine carburetor utilizes a non-convoluted, planar, flexible diaphragm which does not require a molding process to form a traditional convolution. The diaphragm defines in part a pressure controlled fuel metering chamber on one side and a reference chamber at atmospheric pressure on the other side. During operation of the engine, sub-atmospheric pressure within a fuel and air mixing passage draws fuel from the metering chamber to mix with air for combustion within the engine. As pressure within the metering chamber thus decreases, the diaphragm flexes into metering chamber. The displacement of the diaphragm actuates a flow control valve of the metering system which flows pressurized make-up fuel into the metering chamber until the diaphragm returns to its datum position.

Abstract: A carburetor having a plurality of restricted fluid flow paths upstream of a fuel and air mixing passage to inhibit the passage of large fuel vapor bubbles through the fuel paths and to the fuel and air mixing passage. Desirably, the restricted flow paths constrain large volume vapor bubbles and clusters of bubbles from passing therethrough undistributed in the fuel to prevent an inconsistent or overly lean fuel and air mixture from being delivered to the engine. At least two restrictive flow paths diffuse, separate, and/or break up the large vapor bubbles and clusters into a plurality of smaller vapor bubbles which are more uniformly distributed within the liquid fuel flowing through the carburetor to provide a more consistent flow of fuel to the engine.

Abstract: A fuel injection system for a two-stroke small engine has a charge forming device with an injector mixing passage which forms a rich fuel and air mixture supplied to a tuned injector tube connected adjacent one end through a port to the engine cylinder and adjacent the other end to the engine crankcase. The charge forming device has a high speed fuel circuit which supplies at least a majority of the fuel to the mixing passage under wide open throttle operating conditions and preferably a minor portion of the fuel is also supplied by an idle fuel circuit which under engine idle conditions preferably supplies essentially all of the fuel to the engine. A separate inlet air flow passage of the charge forming device also supplies primarily air to the crankcase of the engine for transfer to the cylinder.

Abstract: A two stroke combustion engine, equipped with fuel injection apparatus and ignition timing controlled by throttle position, has a charge forming device which delivers a rich fuel mixture from an integral float-type fuel chamber. The fuel injection apparatus typically comprises a tuned injector tube that communicates between a crankcase injector port and a cylinder injector port. The vast majority of fuel mixes with air in an injector mixing passage of the charge forming device where it is subsequently delivered to the tuned injector tube which directly injects the rich fuel mixture into a cylinder of the engine. The rich fuel mixture supplied by the charge forming device injects into the combustion chamber through the cylinder injector port via a reflected pressure wave generated from the previous combustion cycle.

Abstract: An engine fuel apparatus has a fuel and air mixing passage through which a rich fuel and air mixture is provided to an engine to support the operation of the engine at idle and low speed, low load engine operation, and a pressurized fuel delivery passage provides liquid fuel to a downstream fuel injector for operation of the engine at high load, high speed and wide open throttle engine operating conditions. A shut-off valve prevents the flow of fuel to the mixing passage when a throttle valve therein, which controls engine operation, is opened a predetermined amount from idle to prevent the flow of the fuel into the mixing passage at high load and/or high speed engine operation. Another shut-off valve prevents the flow of pressurized fuel to the downstream fuel injector device when the throttle valve is between idle and a predetermined position off of idle to prevent the flow of pressurized fuel to the fuel injector device under low speed, low load engine operation.

Abstract: A two stroke combustion engine, equipped with fuel injection apparatus and ignition timing controlled by throttle position, has a charge forming device which delivers a rich fuel mixture from an integral float-type fuel chamber. The fuel injection apparatus typically comprises a tuned injector tube that communicates between a crankcase injector port and a cylinder injector port. The vast majority of fuel mixes with air in an injector mixing passage of the charge forming device where it is subsequently delivered to the tuned injector tube which directly injects the rich fuel mixture into a cylinder of the engine. The rich fuel mixture supplied by the charge forming device injects into the combustion chamber through the cylinder injector port via a reflected pressure wave generated from the previous combustion cycle.

Abstract: A fuel injection system for a two-stroke small engine has a charge forming device with an injector mixing passage which forms a rich fuel and air mixture supplied to a tuned injector tube connected adjacent one end through a port to the engine cylinder and adjacent the other end to the engine crankcase. The charge forming device has a high speed fuel circuit which supplies at least a majority of the fuel to the mixing passage under wide open throttle operating conditions and preferably a minor portion of the fuel is also supplied by an idle fuel circuit which under engine idle conditions preferably supplies essentially all of the fuel to the engine. A separate inlet air flow passage of the charge forming device also supplies primarily air to the crankcase of the engine for transfer to the cylinder.

Abstract: A two-stroke internal combustion engine having at least one cylinder with a combustion chamber defined between the cylinder head and a reciprocating piston, and a carburetor which delivers a rich fuel and air mixture to a compressor with a reciprocating piston driven by the engine to compress the mixture until the mixture is under sufficient pressure to open a differential pressure injection valve and thereby inject the mixture directly into the engine combustion chamber. The mixture is ignited by a spark plug to drive the engine piston through its power stroke and rotate its associated crankshaft which is connected to a crankshaft of the compressor to reciprocate its piston and thereby compress the fuel and air mixture and inject it into the cylinder in timed relation with the engine piston.

Abstract: An internal combustion engine has a fuel and air mixing device which utilizes an open bore venturi to draw fuel from the device and deliver a rich fuel and air mixture to a compressor driven by the engine for direct injection of the rich fuel and air mixture into the engine. An engine air throttle body uses an engine throttle linkage and valve to control air flow into the engine crankcase and provides a positive air pressure signal, especially at small throttle openings, to assist the metering of fuel within the fuel and air metering device. The positive air pressure signal is preferably provided by a small port in the engine air throttle body slightly downstream of the throttle valve when closed and is communicated with the fuel and air metering device to cause additional fuel to be delivered from the device.