A generator includes an internal combustion engine including an engine block including a cylinder including a piston, a crankshaft configured to rotate about a crankshaft axis in response to movement by the piston, and a spark plug configured to periodically generate a spark to ignite fuel in the cylinder to control the movement of the piston. The generator further includes an alternator including a rotor and a stator, the rotor configured to rotate with the rotation of the crankshaft to generate alternating current electrical power, a controller configured to control a rate of fuel supply to the internal combustion engine, and a switch configured to selectively enable the flow of a first type of fuel into the cylinder and disable the flow of a second type of fuel, wherein the controller is configured to receive an indication of a fuel type based on a position of the switch.