A dual fuel engine includes an engine operable on a gaseous fuel and a liquid fuel and has an electrical power generator. The dual fuel engine also includes a carburetor attached to an intake of the engine to mix air and fuel and connect to a gaseous fuel source and a liquid fuel source. A liquid fuel cut-off connects to the carburetor to selectively interrupt a flow of liquid fuel to the engine. The liquid fuel cut-off is operable in open and closed states such that the liquid fuel cut-off interrupts the flow of liquid fuel when closed. The dual fuel engine also includes controller operably connected to operate the liquid fuel cut-off in the open and closed states, and the controller may be programmed to implement a delay period upon engine startup before closing the liquid fuel cut-off.

A multi-fuel engine includes an engine operable on a liquid fuel and a gaseous fuel. The multi-fuel engine also includes a liquid cutoff solenoid coupled to open and close a liquid fuel path to the engine, and a gaseous cutoff solenoid coupled to open and close a gaseous fuel source to the engine. A switch couples a power source to the liquid cutoff solenoid and the gaseous cutoff solenoid to switch between fuel sources on-the-fly during engine operation.

A gaseous fuel and air mixing venturi device is adapted for installation in a gaseous fuel carburetor and has a venturi body defining annular inner and outer venturi passageways which each have a throat of reduced cross-sectional area and have inlet ends in communication with an air inlet of the carburetor. A fuel inlet is configured for connection to a fuel port of the carburetor, and communicates with a plurality of fuel supply ports in the body communicating radially with the inner and outer venturi passages to mix with the air flowing in the passageways.

A gaseous fuel and air mixing venturi device is adapted for installation in a gaseous fuel carburetor and has a venturi body defining annular inner and outer venturi passageways which each have a throat of reduced cross-sectional area and have inlet ends in communication with an air inlet of the carburetor. A fuel inlet is configured for connection to a fuel port of the carburetor, and communicates with a plurality of fuel supply ports in the body communicating radially with the inner and outer venturi passages to mix with the air flowing in the passageways.

A fuel selector for use with a dual fuel generator includes a selector plate, a first fuel valve assembly positioned adjacent the selector plate and actuatable between an ON position and an OFF position to selectively control a first fuel flow to an engine of the dual fuel generator, and a second fuel valve assembly positioned adjacent the selector plate and actuatable between an ON position and an OFF position to selectively control a second fuel flow to the engine of the dual fuel generator. A selector switch coupled to the selector plate is linearly translatable from a first position to a second position, so as to enable positioning of only one of the first fuel valve assembly and the second fuel valve assembly in the ON position at a given time, such that the first and second fuel valve assemblies cannot be in the ON position concurrently.

A fuel selector for use with a dual fuel generator includes a selector plate, a first fuel valve assembly positioned adjacent the selector plate and actuatable between an ON position and an OFF position to selectively control a first fuel flow to an engine of the dual fuel generator, and a second fuel valve assembly positioned adjacent the selector plate and actuatable between an ON position and an OFF position to selectively control a second fuel flow to the engine of the dual fuel generator. A selector switch coupled to the selector plate is linearly translatable from a first position to a second position, so as to enable positioning of only one of the first fuel valve assembly and the second fuel valve assembly in the ON position at a given time, such that the first and second fuel valve assemblies cannot be in the ON position concurrently.

A fuel selector for use with a dual fuel generator includes a selector plate, a first fuel valve assembly positioned adjacent the selector plate and actuatable between an ON position and an OFF position to selectively control a first fuel flow to an engine of the dual fuel generator, and a second fuel valve assembly positioned adjacent the selector plate and actuatable between an ON position and an OFF position to selectively control a second fuel flow to the engine of the dual fuel generator. A selector switch coupled to the selector plate is linearly translatable from a first position to a second position, so as to enable positioning of only one of the first fuel valve assembly and the second fuel valve assembly in the ON position at a given time, such that the first and second fuel valve assemblies cannot be in the ON position concurrently.

A fuel selector for use with a dual fuel generator includes a selector plate, a first fuel valve assembly positioned adjacent the selector plate and actuatable between an ON position and an OFF position to selectively control a first fuel flow to an engine of the dual fuel generator, and a second fuel valve assembly positioned adjacent the selector plate and actuatable between an ON position and an OFF position to selectively control a second fuel flow to the engine of the dual fuel generator. A selector switch coupled to the selector plate is linearly translatable from a first position to a second position, so as to enable positioning of only one of the first fuel valve assembly and the second fuel valve assembly in the ON position at a given time, such that the first and second fuel valve assemblies cannot be in the ON position concurrently.

An automatic gas-fuel switching system includes a gas source, a fuel source, a pressure reducing valve, and a carburetor, where the fuel source is connected to the carburetor through a fuel pipe, and a fuel passage is formed inside the carburetor; the gas source is connected to the pressure reducing valve through a first gas pipe, and the pressure reducing valve is connected to the carburetor through a second gas pipe; the carburetor is provided with a pneumatic lifting mechanism that includes a housing, the housing is provided with a gas inlet, and a pneumatic elastic member and an ejector pin connected to each other are disposed within the housing; and a branch pipe connected to the gas inlet is disposed on the first gas pipe. Compared to the prior art, in the present disclosure, switching between gas and fuel is achieved solely by operating the gas source.

An automatic gas-fuel switching system includes a gas source, a fuel source, a pressure reducing valve, and a carburetor, where the fuel source is connected to the carburetor through a fuel pipe, and a fuel passage is formed inside the carburetor; the gas source is connected to the pressure reducing valve through a first gas pipe, and the pressure reducing valve is connected to the carburetor through a second gas pipe; the carburetor is provided with a pneumatic lifting mechanism that includes a housing, the housing is provided with a gas inlet, and a pneumatic elastic member and an ejector pin connected to each other are disposed within the housing; and a branch pipe connected to the gas inlet is disposed on the first gas pipe. Compared to the prior art, in the present disclosure, switching between gas and fuel is achieved solely by operating the gas source.