Abstract: An internal combustion engine includes an engine body defining a combustion chamber, an ignition device configured to ignite mixture in the combustion chamber, an operation device configured to receive a stop operation to stop the internal combustion engine, a controller configured to stop the ignition device from igniting the mixture in response to reception of the stop operation by the operation device, a carburetor configured to supply fuel to an intake passage that communicates with the combustion chamber, a switching valve provided in the intake passage, and an adjustment device configured to adjust an opening degree of the switching valve, wherein the adjustment device is configured to close the switching valve in conjunction with the reception of the stop operation by the operation device.

Abstract: An internal combustion engine includes an engine body defining a combustion chamber, an ignition device configured to ignite mixture in the combustion chamber, an operation device configured to receive a stop operation to stop the internal combustion engine, a controller configured to stop the ignition device from igniting the mixture in response to reception of the stop operation by the operation device, a carburetor configured to supply fuel to an intake passage that communicates with the combustion chamber, a switching valve provided in the intake passage, and an adjustment device configured to adjust an opening degree of the switching valve, wherein the adjustment device is configured to close the switching valve in conjunction with the reception of the stop operation by the operation device.

Abstract: A fuel supply system includes an intake flow passage communicating with an intake port of a gas engine, a fuel shut-off valve assembly for blocking a fuel supply passage to prevent supply of a gas fuel to a fuel mixer, a vacuum flow passage communicating with a vacuum actuator of the fuel shut-off valve assembly and a crank chamber of the gas engine, and means for holding the vacuum flow passage open when the gas engine starts, such that a vacuum produced in the crank chamber is used to actuate the vacuum actuator for switching the fuel shut-off valve assembly to an open position allowing supply of the gas fuel to the fuel mixer.

Abstract: An engine working machine that has an electronically controlled fuel injection system and a fuel tank disposed in an upper portion. The capacity of the fuel tank is effectively used and a complex structure is prevented while reducing the length of the fuel piping. An engine is disposed in a lower portion, and a fuel tank is disposed above the engine. A fuel pump is mounted on a bottom outside surface of the fuel tank, and disposed projecting on a side portion of the crankcase. An extended box is provided on a bottom surface of the fuel tank, and the fuel pump is mounted with a filter and a fuel intake port located inside the extended box. The fuel pump is housed in a pump case that is fixed to a bottom surface of the extended box.

Abstract: A fuel supply system includes an intake flow passage communicating with an intake port of a gas engine, a fuel shut-off valve assembly for blocking a fuel supply passage to prevent supply of a gas fuel to a fuel mixer, a vacuum flow passage communicating with a vacuum actuator of the fuel shut-off valve assembly and a crank chamber of the gas engine, and means for holding the vacuum flow passage open when the gas engine starts, such that a vacuum produced in the crank chamber is used to actuate the vacuum actuator for switching the fuel shut-off valve assembly to an open position allowing supply of the gas fuel to the fuel mixer.

Abstract: An engine working machine that has an electronically controlled fuel injection system and a fuel tank disposed in an upper portion. The capacity of the fuel tank is effectively used and a complex structure is prevented while reducing the length of the fuel piping. An engine is disposed in a lower portion, and a fuel tank is disposed above the engine. A fuel pump is mounted on a bottom outside surface of the fuel tank, and disposed projecting on a side portion of the crankcase. An extended box is provided on a bottom surface of the fuel tank, and the fuel pump is mounted with a filter and a fuel intake port located inside the extended box. The fuel pump is housed in a pump case that is fixed to a bottom surface of the extended box.