SPARK IGNITION INTERNAL COMBUSTION GAS ENGINE

The invention relates to a spark ignition internal combustion gas engine (1), whose fuel system comprises a fuel tank with a main gaseous fuel and a fuel tank with a second gaseous fuel differing from the main fuel, whereby the engine cylinder(10) comprises an ignition chamber (18), in which is arranged a means for igniting the gas fuel located therein, whereby the ignition chamber (18) is connected via the interconnecting holes (20) to the main combustion space (13), whereby the pure main fuel feed opens into a supply duct (14) in front of a suction valve (16) of the cylinder (10), whereby the internal combustion engine is coupled to an engine control unit to monitor the current state of the engine operation and, depending on it, to control at least the fuel system, ignition timing system and the engine performance. The fuel system comprises a gaseous fuel mixer (6) connected to a main gaseous fuel supply (3) of the main gaseous fuel and to a supply (4) of the second gaseous fuel, whereby a means for setting the mutual ratio of the mixing of the main fuel and the second fuel in the mixer (6) is coupled to the engine control unit, whereby from the mixer (6) extends an supply pipe (61) of auxiliary fuel to the engine (1), which opens into the ignition chamber (18).