Abstract: An internal combustion engine that burns fuel from a fuel source, and an engine including a block assembly with a piston cylinder, a combustion chamber connected to the piston cylinder, and an air/fuel mixing area that communicates with the combustion chamber for delivering an air/fuel mixture to the combustion chamber. A fuel delivery system is connected to the block assembly, and the fuel delivery system is adapted to deliver a selected amount of fuel into the mixing area for mixing with air therein to provide an air/fuel mixture having an air-to-fuel ratio in the range of approximately 20:1 to 45:1, inclusive. A spark plug is connected to the block assembly and positioned to generate a spark in the combustion chamber to detonate the air/fuel mixture. The spark plug has a center electrode and a ground electrode axially spaced apart from each other by a spark gap in the range of approximately 1.8 mm to 3.0 mm.

Abstract: A spark plug for an internal combustion engine that burns fuel from a fuel source, the engine including a block assembly with a piston cylinder, a fluid combustion chamber connected to the piston cylinder, and an air and fuel mixing area that communicates with the combustion chamber for delivering an air and fuel mixture to the combustion chamber. A fuel delivery system is connected to the block assembly, and the fuel delivery system has a fuel passage that communicates with the fuel mixing area. The fuel delivery system has a delivery nozzle connected to the fuel passage and being directed toward the fuel mixing area, and the delivery nozzle is sized to spray a selected amount of fuel into the mixing area for mixing with air therein to provide an air and fuel mixture having an air-to-fuel ratio in the range of 90:1 to 240:1. A fuel line is connected to the fuel source and the fuel delivery system to carry the fuel from the fuel tank to the fuel delivery system.