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.

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 may include a body having a main bore from which a fuel and air mixture is discharged for use by an engine, a throttle valve head, a choke valve head and a flow directing feature. The throttle valve head may be carried by the body and is moveable between an idle position and a wide open position to control at least some fluid flow through the main bore. The choke valve head may also be carried by the body and is moveable between a first position and a second position to at least in part control fluid flow through the main bore. And the flow directing feature associated with the choke valve head or the throttle valve head may alter at least one of the velocity or direction of at least a portion of the fluid that flows in the main bore.

An electronic carburetor injection system is provided for an internal combustion engine. The electronic carburetor injection system is a standalone, user programmable fuel injection system that delivers additional fuel to the engine whenever a lean fuel/air mixture is delivered by a carburetor. The electronic carburetor injection system includes a fuel injector that delivers liquid fuel in the form of a spray discharge. A plate supports the fuel injector between the carburetor and an intake manifold of the engine. The plate includes an injector port that allows the spray discharge to enter the intake manifold without interfering with operating the carburetor. An engine control unit operates the fuel injector according to signals received from an oxygen sensor that is disposed within an exhaust system of the engine. During operation, the electronic carburetor injection system maintains the fuel/air mixture within a proper range across multiple driving conditions and changing environmental conditions.

An electronic carburetor injection system is provided for an internal combustion engine. The electronic carburetor injection system is a standalone, user programmable fuel injection system that delivers additional fuel to the engine whenever a lean fuel/air mixture is delivered by a carburetor. The electronic carburetor injection system includes a fuel injector that delivers liquid fuel in the form of a spray discharge. A plate supports the fuel injector between the carburetor and an intake manifold of the engine. The plate includes an injector port that allows the spray discharge to enter the intake manifold without interfering with operating the carburetor. An engine control unit operates the fuel injector according to signals received from an oxygen sensor that is disposed within an exhaust system of the engine. During operation, the electronic carburetor injection system maintains the fuel/air mixture within a proper range across multiple driving conditions and changing environmental conditions.

A simple engine, comprises (1) a cylinder and a spark plug in the cylinder; (2) a carburetor, fluidly connected to the cylinder; (3) a primary air intake path, fluidly connecting atmosphere to the carburetor; (4) a carburetor bypass air intake path, fluidly connecting air to the cylinder without passing through the carburetor; and (5) a valve, along the carburetor bypass air intake path, for controlling the flow of air through the carburetor bypass air intake path.

A simple engine, comprises (1) a cylinder and a spark plug in the cylinder; (2) a carburetor, fluidly connected to the cylinder; (3) a primary air intake path, fluidly connecting atmosphere to the carburetor; (4) a carburetor bypass air intake path, fluidly connecting air to the cylinder without passing through the carburetor; and (5) a valve, along the carburetor bypass air intake path, for controlling the flow of air through the carburetor bypass air intake path.