Abstract: A fuel tank comprises an upper-half tank body (7) and a lower-half tank body (8) which are made of bowl-shaped steel plates and which integrally include a flange (7f) and a flange (8f) in their peripheral edges, respectively, the flanges (7f, 8f) being superposed on and liquid-tightly connected to each other. The flanges (7f, 8f) are connected together by crimping into a roll shape to form an annular thick-walled connection (12), and an annular reinforcing rib (7r, 8r) leading to the connection (12) is formed at least in one of the upper-half and lower-half tank bodies (7, 8). Thus, it is possible to provide a fuel tank in which a sufficient strength can be imparted to portions around a flange connection, without particularly increasing the thickness of a steel plate.

Abstract: An air-cooled engine for a working machine includes a fan cover, a muffler protector, and an insulator. The fan cover has a guide opening for guiding a cooling air toward an exhaust muffler. The muffler protector has air discharge holes for discharging the cooling air, which has been introduced through the guide opening into a guide passage, in a direction away from the working machine. The insulator has a deflector section bent toward a carburetor so that the cooling air having passed through another guide passage between the insulator and cylinder barrel is guided by the deflector section in a direction away from the working machine.

Abstract: An air-cooled engine for a working machine includes a fan cover, a muffler protector, and an insulator. The fan cover has a guide opening for guiding a cooling air toward an exhaust muffler. The muffler protector has air discharge holes for discharging the cooling air, which has been introduced through the guide opening into a guide passage, in a direction away from the working machine. The insulator has a deflector section bent toward a carburetor so that the cooling air having passed through another guide passage between the insulator and cylinder barrel is guided by the deflector section in a direction away from the working machine.

Abstract: A plastic fuel tank having polyethylene layers is disclosed. The polyethylene layer positioned as the outermost layer of the plastic fuel tank is a high-density polyethylene layer admixed with an ultraviolet inhibitor for minimizing transmission of ultraviolet light.

Abstract: A plastic fuel tank is disclosed including polyethylene layers laminated respectively onto an upper surface and a lower surface of an ethylene/vinyl alcohol layer for preventing fuel seepage. The outermost polyethylene layer laminated onto the upper surface is a high-density polyethylene layer colored black so as to minimize transmission of ultraviolet light.

Abstract: A tank cap includes: a synthetic-resin cap body (20) mounted on a fuel supply port cylinder (18) of a conductive fuel tank, (T); a conductive cap shell (22) coupled to an upper part of the cap body (20); and a gasket (23) provided in the cap body (20) and in close contact with a sealing surface (18a) of the fuel supply port cylinder (18). The cap body (20) and the cap shell (22) are linked to be mutually rotatable. A ratchet mechanism (35) is mounted between the cap shell (22) and the cap body (20). An elastic contact piece (38) elastically and slidably contacting an inner peripheral surface of a cylindrical peripheral wall (22a) of the cap shell (22) is integrally projectingly provided on an outer periphery of the gasket (23). Thus, it is possible to cause static electricity carried by an operator to escape to a fuel tank through the gasket.

Abstract: A fuel feed system of an engine is provided with a gas-fuel separating unit for separating oil mist generated in an engine case from air with a labyrinth, and an auto fuel cock is operated by pressure pulsation of the air from which the oil mist is separated by the gas-liquid separating unit. Thus, infiltration of the oil mist into the auto fuel cock is suppressed to the minimum, and a malfunction of the auto fuel cock caused by accumulation of the oil can be prevented. Additionally, a breather passage for feeding the air, from which the oil mist is separated by the gas-liquid separating unit, to a breathing unit is connected the auto fuel cock via a negative pressure tube. Thus, it is unnecessary to provide a specific passage for transmitting the pressure pulsation of the air in the engine case to the auto fuel cock.

Abstract: An engine air intake system for an engine-powered working machine includes a lever cover which covers at least a base portion of an operation control lever mounted on an operation handle for operation by a human operator to control operation of at least one of the working machine and an engine of the working machine, a lower cover disposed inside the lever cover so as to define jointly with the lever cover a hollow space, an air intake portion having an air inlet opening and disposed in the lever cover such that at least the air inlet opening is disposed within the hollow space, and a fresh air guide hose interconnecting the air intake portion and the interior of an air-cleaner case.

Abstract: A plastic fuel tank having polyethylene layers is disclosed. The polyethylene layer positioned as the outermost layer of the plastic fuel tank is a high-density polyethylene layer admixed with an ultraviolet inhibitor for minimizing transmission of ultraviolet light.

Abstract: A plastic fuel tank is disclosed including polyethylene layers laminated respectively onto an upper surface and a lower surface of an ethylene/vinyl alcohol layer for preventing fuel seepage. The outermost polyethylene layer laminated onto the upper surface is a high-density polyethylene layer colored black so as to minimize transmission of ultraviolet light.

Abstract: A fuel feed system of an engine is provided with a gas-fuel separating unit for separating oil mist generated in an engine case from air with a labyrinth, and an auto fuel cock is operated by pressure pulsation of the air from which the oil mist is separated by the gas-liquid separating unit. Thus, infiltration of the oil mist into the auto fuel cock is suppressed to the minimum, and a malfunction of the auto fuel cock caused by accumulation of the oil can be prevented. Additionally, a breather passage for feeding the air, from which the oil mist is separated by the gas-liquid separating unit, to a breathing unit is connected the auto fuel cock via a negative pressure tube. Thus, it is unnecessary to provide a specific passage for transmitting the pressure pulsation of the air in the engine case to the auto fuel cock.

Abstract: An engine air intake system for an engine-powered working machine includes a lever cover which covers at least a base portion of an operation control lever mounted on an operation handle for operation by a human operator to control operation of at least one of the working machine and an engine of the working machine, a lower cover disposed inside the lever cover so as to define jointly with the lever cover a hollow space, an air intake portion having an air inlet opening and disposed in the lever cover such that at least the air inlet opening is disposed within the hollow space, and a fresh air guide hose interconnecting the air intake portion and the interior of an air-cleaner case.

Abstract: To a first bank B1 and a second bank B2, a first throttle body T1 and a second throttle body T2 placed between the banks B1, B2 are attached, respectively, in such a manner that an axis A3 of an intake path 8 of each of the first throttle body T1 and the second throttle body T2 is substantially perpendicular to an axis A2 of a corresponding one of the banks B1, B2. Each of the throttle bodies T1, T2 has a throttle valve 9 pivotally supported therein and the fuel injection valve 10 injecting fuel to the intake path 8 at a part downstream of the throttle valve 9. The throttle valve 9 of each of the first and second throttle bodies T1, T2 is placed in such a manner that an axis A4 of a valve shaft 9a of the throttle valve 9 is substantially orthogonal to the axis A3 of the corresponding intake path 8 and is substantially parallel to the axis A2 of a corresponding one of the banks B1, B2.

Abstract: A fuel tank comprises an upper-half tank body (7) and a lower-half tank body (8) which are made of bowl-shaped steel plates and which integrally include a flange (7f) and a flange (8f) in their peripheral edges, respectively, the flanges (7f, 8f) being superposed on and liquid-tightly connected to each other. The flanges (7f, 8f) are connected together by crimping into a roll shape to form an annular thick-walled connection (12), and an annular reinforcing rib (7r, 8r) leading to the connection (12) is formed at least in one of the upper-half and lower-half tank bodies (7, 8). Thus, it is possible to provide a fuel tank in which a sufficient strength can be imparted to portions around a flange connection, without particularly increasing the thickness of a steel plate.

Abstract: A tank cap includes: a synthetic-resin cap body (20) mounted on a fuel supply port cylinder (18) of a conductive fuel tank, (T); a conductive cap shell (22) coupled to an upper part of the cap body (20); and a gasket (23) provided in the cap body (20) and in close contact with a sealing surface (18a) of the fuel supply port cylinder (18). The cap body (20) and the cap shell (22) are linked to be mutually rotatable. A ratchet mechanism (35) is mounted between the cap shell (22) and the cap body (20). An elastic contact piece (38) elastically and slidably contacting an inner peripheral surface of a cylindrical peripheral wall (22a) of the cap shell (22) is integrally projectingly provided on an outer periphery of the gasket (23). Thus, it is possible to cause static electricity carried by an operator to escape to a fuel tank through the gasket.

Abstract: An engine includes a cylinder head having a valve-operating chamber. A cylinder head is coupled to a cylinder block by a plurality of fastening bolts. A head cover is coupled to the cylinder head to close the valve-operating chamber. A ventilating gap is defined between a face of the cylinder head fastened by the fastening bolts and a bottom wall of the valve-operating chamber. An operating bore is provided in the bottom wall to enable insertion of at least one of the fastening bolts and a tool for tightening the fastening bolt. A plug is integrally provided in the head cover to be liquid-tightly fitted into the operating bore. Cooling of portions around the bottom wall of the valve-operating chamber is improved, while the cylinder head can be fastened to the cylinder block from the side of the valve-operating chamber by the fastening bolts.

Abstract: An engine includes a cylinder head having a valve-operating chamber. A cylinder head is coupled to a cylinder block by a plurality of fastening bolts. A head cover is coupled to the cylinder head to close the valve-operating chamber. A ventilating gap is defined between a face of the cylinder head fastened by the fastening bolts and a bottom wall of the valve-operating chamber. An operating bore is provided in the bottom wall to enable insertion of at least one of the fastening bolts and a tool for tightening the fastening bolt. A plug is integrally provided in the head cover to be liquid-tightly fitted into the operating bore. Cooling of portions around the bottom wall of the valve-operating chamber is improved, while the cylinder head can be fastened to the cylinder block from the side of the valve-operating chamber by the fastening bolts.