A method of adjusting operation of an internal combustion engine includes injecting fuel into cylinders of the internal combustion engine (first fuel operation); obtaining a first fuel exhaust temperature profile during the first fuel operation; injecting two fuels into the cylinders in a duel fuel operation; obtaining a duel fuel exhaust temperature profile; and adjusting the injection quantity and/or an injection timing of one fuel in a cylinder(s), based on a difference between the first fuel exhaust temperature profile and the duel fuel exhaust temperature profile. Other methods of operating with single fuel and using sensors other than exhaust temperature sensors are disclosed.

A gas fuel supply system for supplying the gas fuel via an opening of an intake supply pipe that is connected to a combustion chamber in an engine operable in each of a gas fuel combustion mode and an oil fuel combustion mode includes: the gas fuel supply valve for regulating an amount of the gas fuel, the gas fuel supply valve having plural gas supply holes, from which the gas fuel is fed in a direction toward the opening when the valve is opened; and an opening regulation valve provided between the gas fuel supply valve and the opening and having an opening hole, an opening area of which can be regulated. The gas fuel supply system is configured that extended axes of all the gas supply holes pass through the fully opened opening hole.

A dual fuel engine includes an engine operable on a gaseous fuel and a liquid fuel and a switch to change operation of the engine between gaseous fuel and liquid fuel. 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 attaches to the carburetor to interrupt liquid fuel upon actuation of the switch from liquid fuel to gaseous fuel.

A multi-fuel engine includes an engine operable on a liquid fuel and first and second gaseous fuels. The multi-fuel engine also includes a liquid cutoff solenoid selectively operable between open and closed positions to allow and inhibit a flow of the liquid fuel to the engine and at least one gaseous cutoff valve selectively operable between open and closed positions to allow and inhibit a flow of the first and second gaseous fuels to the engine. A jet block couples the first gaseous fuel source and the second gaseous fuel source to a carburetor connected to an intake of the engine, with the jet block being located downstream from the at least one gaseous cutoff valve. The jet block includes a first gaseous fuel jet to meter the first gaseous fuel to the carburetor and a second gaseous fuel jet to meter the second gaseous fuel to the carburetor.

A generator and off-board fuel delivery system is disclosed. The generator is configured to operate on one or more fuels, including on a gaseous fuel supplied from a pressurized fuel source through a gaseous fuel line. A fuel regulator system is located off board the generator and is configured to regulate the gaseous fuel supplied from the pressurized fuel source in a first stage, with the gaseous fuel regulated down to a reduced pressure in the first stage. A second stage of the fuel regulator system regulates the reduced pressure gaseous fuel, with the reduced pressure gaseous fuel from the first stage regulated down to a desired pressure in the second stage for delivery through the gaseous fuel line to operate the generator.

An engine including a main fuel injection valve, a pilot fuel injection valve, a liquid fuel supply rail pipe, and a pilot fuel supply rail pipe. The main fuel injection valve supplies liquid fuel from the liquid fuel supply rail pipe to a combustion chamber during combustion in a diffusion combustion system. The pilot fuel injection valve supplies pilot fuel from the pilot fuel supply rail pipe to the combustion chamber in order to ignite gaseous fuel during combustion in a premixed combustion system. The liquid fuel supply rail pipe is disposed at one side of an imaginary vertical plane (P1) including an axis of a crank shaft. The pilot fuel supply rail pipe is disposed at the side of the imaginary vertical plane at which the liquid fuel supply rail pipe is disposed.

A movable electrical generation system includes a generator operable to produce a supply of electrical energy, a prime mover operable to drive the generator, a first fuel, a second fuel different from the first fuel, a control system operable to deliver one of the first fuel and the second fuel to the prime mover and to control an electrical load applied to the generator based on one of a first fuel current protection limit and a second fuel current protection limit.

A movable electrical generation system includes a generator operable to produce a supply of electrical energy, a prime mover operable to drive the generator, a first fuel, a second fuel different from the first fuel, and a fuel selector valve assembly operable to selectively deliver the first fuel and the second fuel to the prime mover, wherein in response to a transition from delivery of the first fuel to the prime mover to delivery of the second fuel to the prime mover, both the first and second fuels are delivered to the prime mover before cessation of delivery of the first fuel.

A dual-fuel integrated switch includes a bracket. A valve body is provided on one side of the bracket. The inside of the valve body is provided with a spool adapted to the valve body. The spool rotates in the valve body. The first flow passage and the second flow passage communicating with the first flow passage are provided in the spool, an arc-shaped groove is provided on the outer wall of the spool, and the third flow passage adapted to the groove is provided on the side wall of the valve body. The number of the third flow passages is two, and the arc formed by the third flow passage on the side wall of the valve body is the same as the arc at the outer end of the side wall of the groove.

A method for detecting reverse flow for a dual fuel engine is disclosed. The engine may include an intake manifold, a liquid fuel supply line and a gaseous fuel supply line, the gaseous fuel supply line including a gaseous fuel supply and a gaseous fuel rail. The method may include: operating the dual fuel engine in a liquid fuel only mode via the liquid fuel supply line; determining a reverse flow in the gaseous fuel supply line; and outputting an indication of reverse flow in response to the determination of reverse flow.