Abstract: To effectively suppress strong knock that occurs in the operating region of high load and high rotation in a specific engine having a pre-chamber in a combustion chamber, the engine includes a piston that defines a combustion chamber together with a cylinder block and a cylinder head. The combustion chamber includes a sub-chamber and a main chamber separated from the sub-chamber by a pre-chamber. The specific ratio obtained by dividing a bore/stroke ratio of a cylinder by the volume of the sub-chamber is greater than or equal to 6.6 cm?3 and less than or equal to 57.6 cm?3.

Abstract: A throttle body may have a main bore for supplying a fuel and air mixture to an engine. A throttle valve head may be received in the main bore and movable between idle and wide open positions to control fluid flow through the main bore. A main fuel outlet and a boost venturi may open to the main bore and a flow directing feature may alter the velocity and/or direction of fluid flow in the main bore relative to the fuel outlet or boost venturi. The flow directing feature may be carried by the body, the throttle valve head, or the boost venturi.

Abstract: A throttle body may have a main bore for supplying a fuel and air mixture to an engine. A throttle valve head may be received in the main bore and movable between idle and wide open positions to control fluid flow through the main bore. A main fuel outlet and a boost venturi may open to the main bore and a flow directing feature may alter the velocity and/or direction of fluid flow in the main bore relative to the fuel outlet or boost venturi. The flow directing feature may be carried by the body, the throttle valve head, or the boost venturi.

Abstract: A carburetor includes a body and a fuel bowl coupled to the body. A fuel bowl chamber is defined by the body and the fuel bowl. A fuel supply passageway fluidly couples a fuel supply inlet of the carburetor with the fuel bowl chamber. A fuel metering unit is coupled to the body of the carburetor. A first filter is disposed in one of the fuel supply passageway and the fuel bowl chamber, and a second filter is disposed in the fuel metering unit.

Abstract: A fuel air delivery circuit, system, and method for the intake of an internal combustion engine, that provides an enhanced pressure condition to a supplementary or auxiliary air fuel circuit or circuits in connection with a conventional fuel delivery passage or passages, such as, but not limited to, a main, needle, or other jet, injector port, manifold, plenum, or the like, to provide enhanced vaporization and mixture of the fuel and air, and delivery to an associated intake path, such as the bore of a carburetor, intake runner, or the like, to provide improved throttle response and acceleration, and additionally which supplementary circuit will automatically recharge with fuel when a triggering condition is present, such as under steady state and deceleration conditions.

Abstract: In the preferred embodiments an air flow diverting blade is integral to a base that doubles as a collar designed to co-axially attach to the nozzle tip end of a typical port fuel injector for internal combustion engines. Upon simple manual manipulation of the set rotational angle of the typically externally exposed portion of the port fuel injector along its longitudinal axis, as typical modern port injection systems allow after installation, the angle of the intra-port flow diverting blade can be selectively varied to either straighten existing swirl and increase top end flow, or, introduce lateral directional swirl to whatever angle and intensity in either direction is desired. The functional use of a typical port fuel injector is thereby elevated to a multifunction of tunable fuel and air flow control at the point of induction into a combustion chamber without any modification to existing engine designs or their engine management control systems employed therefore.

Abstract: A carburetor has a housing wherein a control drum is rotatably mounted. A section of an intake channel is formed in the carburetor. A subsection of this section is formed in the control drum. The control drum controls the free flow cross section of the intake channel. A fuel opening is connected to a fuel chamber via an unbranched fuel channel which opens into the subsection of the intake channel. A simple configuration of the carburetor is achieved by the carburetor including an electrically actuated valve which controls the flow of fuel through the fuel channel. For a method for operating an internal combustion engine with a carburetor, a temperature (T) is determined before or during the starting of the engine and that the flow of fuel through the fuel channel during the starting of the engine is controlled in dependence upon the temperature (T).

Abstract: An internal combustion engine includes a crankcase including a crankshaft and at least one cylinder coupled to the crankcase. The at least one cylinder has an intake port and defines an internal combustion chamber. The engine further includes a throttle body assembly with a throttle valve coupled to the intake port of the at least one cylinder and a throttle plate. Additionally, the engine includes a supplementary air inlet fluidly coupled to the intake port and spaced apart from the throttle valve. The supplementary air inlet is configured to receive a flow of air from a location downstream of the throttle plate when the throttle plate is in a fully closed position and the flow of air is directed into the combustion chamber through the intake port for combustion therein.

Abstract: A catalyst control system includes a stop and start module that, during a period that the vehicle is ON between (i) a first time when the vehicle is turned ON and (i) a second time when the vehicle is next turned OFF, selectively shuts down and starts a spark ignition engine of the vehicle. A catalyst light off (CLO) control module initiates a first CLO event for a first engine startup during the period and, when a temperature of a catalyst that receives exhaust output by the engine is less than a predetermined temperature, selectively initiates a second CLO event for a second engine startup during the period. A fuel control module richens fueling of the engine during the first and second CLO events of the period. A spark control module retards spark timing of the engine during the first and second CLO events of the period.

Abstract: A plunger valve. The plunger valve includes a body and a set of flutes on the body configured to reduce wedging during operation and eliminate flutter when connected to a diaphragm. The set of flutes includes at least four flutes and are each symmetrically spaced about the axis of the body. The plunger valve also includes a tip.

Abstract: A carburettor includes a primary air passage (19), an adjustable throttle valve (8) situated within the primary air passage, a fuel supply nozzle (28) communicating with the primary air passage and connected to a fuel metering valve for varying the amount of fuel discharged through the nozzle. The fuel metering valve includes an elongate sleeve (32) movably accommodating an elongate valve member (33). The sleeve and valve member define a fuel inlet space (35). A fuel inlet (37) communicates with the fuel inlet space. A fuel outlet (39) passes through the wall of the sleeve (32) and communicates with the fuel supply nozzle (28). A portion of the outer surface of the valve member (33) is so profiled that the valve member (33) is movable relative to the sleeve (32) such that the area of communication between the fuel inlet space (35) and the outlet (39) varies progressively between a maximum and a minimum value.

Abstract: An internal combustion engine that includes a carburetor having a choke valve and an actuator configured to move the choke valve between a closed choke position and an open choke position. A passageway is configured to direct a pressure pulse from the engine into a fuel chamber of the carburetor. The engine further includes a priming valve at least partially located within the passageway. The priming valve is configured to move between an open primer position that allows the pressure pulse to enter the fuel chamber through the passageway and a closed primer position that substantially restricts the pressure pulse from entering the fuel chamber through the passageway. The priming valve is configured to move between the open primer position and the closed primer position by the actuator when the actuator moves the choke valve between the closed choke position and the open choke position, respectively.

Abstract: An evaporative emissions control system for small internal combustion engines. The system generally includes a charcoal canister and a carburetor with a fuel circuit shutoff valve. The charcoal canister is in fluid communication with the air space above the liquid fuel within the engine fuel tank, and optionally, with the air space above the liquid fuel within the fuel bowl of a fuel bowl-type carburetor. The charcoal canister contains charcoal media which absorbs fuel vapors when the engine is not running. During running of the engine, vacuum within the carburetor induces a flow of atmospheric air through the charcoal canister to purge the collected fuel vapors from the charcoal media, and the fuel vapors pass into the engine for consumption. The carburetor of the engine, which may be either a fuel bowl-type carburetor or a diaphragm carburetor, includes a fuel circuit shutoff valve controlled either by a vacuum signal produced within the engine or by a user-actuated mechanical linkage.

Abstract: An idle fuel supply device for a carburetor has an idle air passage that communicates with an air intake passage and a fuel chamber. A passage extending from a fuel metering chamber is connected to the fuel chamber preferably via a fuel adjusting needle valve. A low speed fuel nozzle hole communicates the fuel chamber with the air intake passage in the vicinity of a throttle valve when in its idle position. A passage communicates with the fuel chamber and the idle air passage, so that fuel and air may mix in at least a portion of the idle air passage.

Abstract: An internal combustion engine including a cylinder, a crankshaft, a reciprocating piston disposed in the cylinder and operably coupled to said crankshaft, and a carburetor.

Abstract: An internal combustion engine including a cylinder, a crankshaft, a reciprocating piston disposed in the cylinder and operably coupled to said crankshaft, and a carburetor.

Abstract: A carburetor for an internal combustion engine of a hand-held working tool has a housing and a suction channel with a venturi section arranged in the housing. The suction channel has an inlet and an outlet for allowing air flow therethrough. A throttle is connected in the suction channel so as to be pivotable. A control chamber is provided and a main fuel channel connects the suction channel and the control chamber. An idle fuel channel connects the suction channel and the control chamber. A bypass, having an air supply line and a fuel supply line, is provided for introducing an auxiliary fuel/air mixture during a starting operation of the internal combustion engine to a location of the suction channel downstream of the throttle in a direction of air flow.