An improved primary pump for a carburetor is provided. The primary pump has a reduced cost and reduced space construction. The primary pump includes: a flexible cap having a cavity; an inlet open to the cavity of the flexible cap; an inlet side path fluidly coupled to the inlet; an inlet side check valve disposed in the inlet side path; an outlet open to the cavity of the flexible cap; an outlet side path fluidly coupled to the outlet; and an outlet side check valve disposed on the outlet side path, wherein at least one among the inlet side check valve and the outlet side check valve comprises a flap formed in a pump diaphragm of a fuel pump of the carburetor.

A fuel supply system for small two-stroke internal combustion engines for e.g. chain saws, line trimmers and similar hand-held power-tools including a diaphragm carburetor (20) equipped with a purging system (80a, 81a) or priming system (80b, 81b) for facilitating starting of the engine (1). Downstream of the diaphragm (30), the carburetor has a fuel valve (60) with a fuel cavity (73), which when the valve is not closed being connected via a fuel conduit (37) to a fuel nozzle (35, 36) in a main air passage (21) in the carburetor. The purging system or priming system including a fuel line (80a; 80b), which is provided with a manually operated pump (81a; 81b) and is connected between a fuel tank (26) and either the fuel cavity (73) or the fuel conduit (37).

A fuel supply system for small two-stroke internal combustion engines for e.g. chain saws, line trimmers and similar hand-held power-tools including a diaphragm carburetor (20) equipped with a purging system (80a, 81a) or priming system (80b, 81b) for facilitating starting of the engine (1). Downstream of the diaphragm (30), the carburetor has a fuel valve (60) with a fuel cavity (73), which when the valve is not closed being connected via a fuel conduit (37) to a fuel nozzle (35, 36) in a main air passage (21) in the carburetor. The purging system or priming system including a fuel line (80a; 80b), which is provided with a manually operated pump (81a; 81b) and is connected between a fuel tank (26) and either the fuel cavity (73) or the fuel conduit (37).

A carburetor drain apparatus includes a carburetor bowl, a fuel supply pipe, a fuel drain pipe, and a bail interface. The carburetor bowl is configured to store fuel and provide the fuel to an air passage. The fuel supply pipe is connected a fuel tank and the carburetor bowl. The fuel drain pipe is connected to the carburetor bowl. The bail interface is configured to operate in response to actuation of a bail to open the fuel drain pipe.

A carburetor drain apparatus includes a carburetor bowl, a fuel supply pipe, a fuel drain pipe, and a bail interface. The carburetor bowl is configured to store fuel and provide the fuel to an air passage. The fuel supply pipe is connected a fuel tank and the carburetor bowl. The fuel drain pipe is connected to the carburetor bowl. The bail interface is configured to operate in response to actuation of a bail to open the fuel drain pipe.

A fuel supply device has a housing and an intake channel section formed in the housing. At least one fuel port opens into the intake channel section. At least one fuel channel is provided and a valve with valve plate is arranged in the fuel channel. The valve has a closed position and an open position. The valve plate contacts a valve seat in the closed position. The valve plate carries out a valve stroke between open position and closed position. At least one annular gap is formed in the fuel channel. A gap width of the at least one annular gap is matched to a length of the valve stroke of the valve plate such that the gap width is not larger than twice a length of the valve stroke. A flow cross section of the annular gap is larger than a flow cross section of the valve.

A carburetor drain apparatus includes a carburetor bowl, a fuel supply pipe, a fuel drain pipe, and a bail interface. The carburetor bowl is configured to store fuel and provide the fuel to an air passage. The fuel supply pipe is connected a fuel tank and the carburetor bowl. The fuel drain pipe is connected to the carburetor bowl. The bail interface is configured to operate in response to actuation of a bail to open the fuel drain pipe.

A carburetor drain apparatus includes a carburetor bowl, a fuel supply pipe, a fuel drain pipe, and a bail interface. The carburetor bowl is configured to store fuel and provide the fuel to an air passage. The fuel supply pipe is connected a fuel tank and the carburetor bowl. The fuel drain pipe is connected to the carburetor bowl. The bail interface is configured to operate in response to actuation of a bail to open the fuel drain pipe.

An improved primary pump for a carburetor is provided. The primary pump has a reduced cost and reduced space construction. The primary pump includes: a flexible cap having a cavity; an inlet open to the cavity of the flexible cap; an inlet side path fluidly coupled to the inlet; an inlet side check valve disposed in the inlet side path; an outlet open to the cavity of the flexible cap; an outlet side path fluidly coupled to the outlet; and an outlet side check valve disposed on the outlet side path, wherein at least one among the inlet side check valve and the outlet side check valve comprises a flap formed in a pump diaphragm of a fuel pump of the carburetor.

A garden tool includes a gasoline engine and a power source, the gasoline engine including a fuel supply system and an ignition system. The garden tool may further include a control system with at least one sensor used for collecting a working condition signal of the gasoline engine and a controller used for receiving the working condition signal and controlling the fuel supply system and/or the ignition system according to the working condition signal received. The power source may provide a power supply for the fuel supply system, the ignition system, and the control system through the controller.