Gas mixer for internal combustion engine

An exemplary gas mixer (20) of a gaseous fuel internal combustion engine for mixing gaseous fuel and air is disclosed. The gas mixer (20) may comprise a housing (36) having an air inlet (42), a gaseous fuel inlet (44), and a mixture outlet (46). The gas mixer (20) may further comprise a mixing passage (40) and a displacement body (38) arranged in the housing (36) and displaceable into the mixing passage (40). The displacement body (38) may have an inner fuel channel (50) fluidly interconnecting the gaseous fuel inlet (44) and the mixing passage (40).