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 carburetor for an internal combustion engine includes a body having an air inlet opening portion, an air outlet opening portion, and a throat portion extending therebetween. A fuel reservoir is in fluid communication with the throat portion. A slide assembly is movably disposed in the body for movement across the throat portion. The slide assembly includes a metering rod extending across the throat portion and into the fuel reservoir. An electrically operable actuator, when operated, adjusts an axial position of the metering rod relative to the fuel reservoir.

A carburetor for an internal combustion engine includes a body having an air inlet opening portion, an air outlet opening portion, and a throat portion extending therebetween. A fuel reservoir is in fluid communication with the throat portion. A slide assembly is movably disposed in the body for movement across the throat portion. The slide assembly includes a metering rod extending across the throat portion and into the fuel reservoir. An electrically operable actuator, when operated, adjusts an axial position of the metering rod relative to the fuel reservoir.

An engine system includes an engine, a carburetor induction system, and a controller. The carburetor induction system is fluidly coupled to the engine to provide an air-fuel mixture thereto. The carburetor induction system includes a pump configured to provide a leaner air-fuel mixture to the engine. The controller is configured to adjust operation of the pump.

An engine system includes an engine, a carburetor induction system, and a controller. The carburetor induction system is fluidly coupled to the engine to provide an air-fuel mixture thereto. The carburetor induction system includes a pump configured to provide a leaner air-fuel mixture to the engine. The controller is configured to adjust operation of the pump.

A simple engine, comprises (1) a cylinder and a spark plug in the cylinder; (2) a carburetor, fluidly connected to the cylinder; (3) a primary air intake path, fluidly connecting atmosphere to the carburetor; (4) a carburetor bypass air intake path, fluidly connecting air to the cylinder without passing through the carburetor; and (5) a valve, along the carburetor bypass air intake path, for controlling the flow of air through the carburetor bypass air intake path.

A simple engine, comprises (1) a cylinder and a spark plug in the cylinder; (2) a carburetor, fluidly connected to the cylinder; (3) a primary air intake path, fluidly connecting atmosphere to the carburetor; (4) a carburetor bypass air intake path, fluidly connecting air to the cylinder without passing through the carburetor; and (5) a valve, along the carburetor bypass air intake path, for controlling the flow of air through the carburetor bypass air intake path.