A carburetor having an inlet opening that includes a pair of concavities operative to direct air toward the metering rod of the carburetor. A carburetor having an inlet opening that includes an arcuate manifold adjacent to the inlet opening and in fluid communication with a fuel reservoir. A carburetor having a slide assembly that includes a positioning mechanism operative to adjust the position of the metering rod relative to the throttle slide. A throttle slide that includes a flow guide that bisects an arcuate relief on an underside thereof. A method for configuring the throat of a carburetor that includes an upper portion of a first diameter and a lower portion of a second diameter that is offset from the first diameter. The method comprises deriving an optimum size for the first and second diameters and the offset based on the pumping efficiency and operating parameters of the engine.

A solenoid valve includes a housing, a bobbin and an armature. The bobbin is received at least partially within the housing and has a body about which a coil is provided. A fluid flow path including an inlet and an outlet and a valve seat is defined by at least one of the housing or the bobbin, and the armature is moveable relative to the valve seat to control flow through the fluid flow path.

In at least some implementations, a throttle body assembly for a combustion engine includes a throttle body having a pressure chamber in which a supply of fuel is received and a throttle bore with an inlet through which air is received, a throttle valve carried by the throttle body with a valve head movable relative to the throttle bore to control fluid flow through the throttle bore, and a metering valve carried by the throttle body. The metering valve may have a valve element that is movable between an open position wherein fuel may flow from the pressure chamber into the throttle bore and a closed position where fuel is prevented or substantially prevented from flowing into the throttle bore through the metering valve.

An attachment structure for a solenoid valve which can be stably attached to and removed from a carburetor unit with a single movement and without increasing the number of parts. A rod-like supporting portion is disposed a predetermined distance away from a surface of a carburetor unit and extending in a direction substantially perpendicular to a direction of and installed near an opening in the surface of the carburetor unit. A cylindrical engaging portion extends from a circumferential face of a cylindrical body fitted on the solenoid valve substantially perpendicular to an axial line of the rod-like supporting portion, and forms a groove-like engagement portion which is narrower in diameter than the rod-like supporting portion, whereby the engaging portion, via the groove-like engagement portion, is coupled to and supported by rod-like supporting portion when an insertion portion of the solenoid valve is inserted into the opening.

An attachment structure for a solenoid valve which can be stably attached to and removed from a carburetor unit with a single movement and without increasing the number of parts. A rod-like supporting portion is disposed a predetermined distance away from a surface of a carburetor unit and extending in a direction substantially perpendicular to a direction of and installed near an opening in the surface of the carburetor unit. A cylindrical engaging portion extends from a circumferential face of a cylindrical body fitted on the solenoid valve substantially perpendicular to an axial line of the rod-like supporting portion, and forms a groove-like engagement portion which is narrower in diameter than the rod-like supporting portion, whereby the engaging portion, via the groove-like engagement portion, is coupled to and supported by rod-like supporting portion when an insertion portion of the solenoid valve is inserted into the opening.

A carburetor, a method of assembling a carburetor, and a method of operating an engine. The carburetor may generally include a housing defining a pump portion and a metering portion; and a maintenance port in communication with the pump portion and the metering portion to allow direct introduction of an additive through the maintenance port and into the pump portion and the metering portion.

A carburetor, a method of assembling a carburetor, and a method of operating an engine. The carburetor may generally include a housing defining a pump portion and a metering portion; and a maintenance port in communication with the pump portion and the metering portion to allow direct introduction of an additive through the maintenance port and into the pump portion and the metering portion.

An operator initiated control process for an engine which tests the air-to-fuel ratio of an air-fuel mixture supplied to the engine when it is in stable operation and if need be changes the air-to-fuel ratio to improve engine performance and/or meet engine exhaust emissions requirements.

A fuel supply device includes a main body, fuel chamber, fuel supply pipe and a fuel valve. The main body has a main bore with an inlet for air and an outlet through which a fuel and air mixture flows. The fuel chamber retains a supply of fuel. The fuel supply pipe has a passage communicating with the main bore and through which fuel from the fuel chamber flows to the main bore. And the fuel valve has a valve seat, a valve element movable relative to the valve seat between an open position and a closed position, an inlet upstream of the valve seat and is in communication with the fuel chamber, and an outlet downstream of the valve seat. The outlet is coaxially aligned with the passage of the fuel supply pipe and the fuel valve is electrically operated to move the valve element.

An attachment structure for a solenoid valve which can be stably attached to and removed from a carburetor unit with a single movement and without increasing the number of parts. A rod-like supporting portion is disposed a predetermined distance away from a surface of a carburetor unit and extending in a direction substantially perpendicular to a direction of and installed near an opening in the surface of the carburetor unit. A cylindrical engaging portion extends from a circumferential face of a cylindrical body fitted on the solenoid valve substantially perpendicular to an axial line of the rod-like supporting portion, and forms a groove-like engagement portion which is narrower in diameter than the rod-like supporting portion, whereby the engaging portion, via the groove-like engagement portion, is coupled to and supported by rod-like supporting portion when an insertion portion of the solenoid valve is inserted into the opening.