An assembly includes a housing including a first assembly portion and a cover including a second assembly portion. One of the first assembly portion and the second assembly portion includes: (i) a small diameter inner circumferential wall, a large diameter inner circumferential wall, and an inner stepped portion; or (ii) a large diameter outer circumferential wall, a small diameter outer circumferential wall, and an outer stepped portion. A method for manufacturing the assembly includes a press-fitting step of fitting the housing and the cover by press-fitting to form a circumferential gap that is open in an axial direction and a welding step of welding the housing and the cover at the circumferential gap.

A carburetor includes a carburetor bowl, a fuel supply pipe, a fuel drain pipe, and a valve. 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 and the fuel supply line. The valve for the fuel drain pipe is configured to open and close in response to an orientation of the carburetor.

A carburetor includes a carburetor bowl, a fuel supply pipe, a fuel drain pipe, and a valve. 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 and the fuel supply line. The valve for the fuel drain pipe is configured to open and close in response to an orientation of the carburetor.

A carburetor includes a carburetor bowl, a fuel supply pipe, a fuel drain pipe, and a valve. 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 and the fuel supply line. The valve for the fuel drain pipe is configured to open and close in response to an orientation of the carburetor.

A carburetor includes a carburetor bowl, a fuel supply pipe, a fuel drain pipe, and a valve. 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 and the fuel supply line. The valve for the fuel drain pipe is configured to open and close in response to an orientation of the carburetor.

A check valve for opening/closing intake-side communication passages through which fuel passes, includes a pump body including a partition wall with the communication passages formed therein, a valve body supported by the partition wall, made of a flexible material, and formed into a plate shape, and a valve seat provided around opening portions of the communication passages on the partition wall and including a seat surface to abut against the valve body when the valve is closed, the seat surface including a groove having an opening-portion-side wall surface lying on an upstream side and an outer-side wall surface lying on a downstream side, the upstream and downstream sides being sides in a direction in which fluid passes between the valve body and the seat surface when the valve is opened, the outer-side wall surface having a gentler slope than a slope of the opening-portion-side wall surface.

In at least some implementations, a carburetor includes a body, a fuel pump diaphragm and a pressure pulse passage. The fuel pump diaphragm is carried by the body and defines in part a fuel chamber on one side of the fuel pump diaphragm and a pressure pulse chamber on the other side of the fuel pump diaphragm. The pressure pulse passage communicates the pressure pulse chamber with a pressure pulse source to provide pressure pulses in the pressure pulse chamber to actuate the fuel pump diaphragm. The pressure pulse passage includes an inlet communicating with a passage in which pressure pulses are present and the inlet is spaced from a surface defining the passage in which pressure pulses are present.

A manually actuated feed pump is provided with a primer bulb to be manually actuated by an operator. The primer bulb has a pump chamber. A travel-controlled valve connects the pump chamber to a fuel line. The travel-controlled valve has a valve member that is moved by an actuation travel of the primer bulb into an open position that opens the travel-controlled valve. A first spring is operatively connected to the valve member and to the primer bulb. The primer bulb acts through the first spring on the valve member.

A handheld work apparatus has a fuel supply system and a pump for delivering fuel from the fuel supply system. The pump has an elastic pump bellows which can be actuated by the operator. The pump bellows has a fastening section at which the pump bellows is fastened to a housing. The pump bellows has a main section and a roof section, wherein the roof section has a dome-shaped section adjoining the main section and a cap which adjoins the dome-shaped section and closes off the dome-shaped section. In order to achieve a rapid return of the pump bellows from the actuated position into the unactuated position, even at low temperatures, it is provided that the smallest wall thickness (g) of the main section is at least 10% greater than the smallest wall thickness (h) of the dome-shaped section.

A diaphragm type fuel pump includes a rod, one end of which is coupled to a diaphragm, a plunger which is slidably fitted with respect to the other end of the rod, and a plunger biasing member which biases the plunger toward the other end of the rod. The other end of the rod has a first pin extending outward radially. A through hole extends through the plunger in a radial direction. The through hole has a size which allows the first pin to move in a longitudinal direction of the rod. The first pin is in contact with one edge of the through hole. A gap is formed between another edge of the through hole and another end surface of the rod. A second pin in parallel to the first pin can be fitted into the gap.