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 base of an engine defines an axial through hole and a pulsation hole channel. An anti-blocking component is mounted inside the axial through hole and defines an air inlet channel. The air inlet channel communicates with the pulsation hole channel so as to avoid blocking of condensed fuel oil inside the pulsation hole channel.

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 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.

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.

An engine apparatus includes a fuel supply system which may comprise a fuel reservoir, primary fuel supply path extending from a fuel inlet in fluid cooperation with the fuel reservoir to a fuel outlet, pressure pulse source, and first and second pressure-operated fuel pumps located along the primary fuel supply path; each of fuel pumps operably coupled to the pressure pulse source. The fuel pumps may be pulse type pumps arranged in series from a flow standpoint along the primary fuel supply path such that fuel discharged by the first fuel pump is supplied to the second fuel pump. The fuel pumps may be mounted and to the engine or appurtenance thereof in a stacked or side-by-side relationship. The pressure pulse source may be the engine crankcase in some designs. The flow and pressures delivered by the series flow fuel pumps are suitable for use with four stroke/cycle engines.

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.