An improved fuel air mixture apparatus which enhances the degree of mixing of fuel with air. The fuel-air mixture device includes a primary air passage having an inlet, an adjustable throttle and an outlet; a secondary air passage having an inlet and an outlet to the primary air passage between its adjustable throttle and its outlet; a nozzle having an orifice opening into the secondary air passage for introducing a flow of fuel therein; a needle arranged co-axially of the nozzle with its small diameter at least normally extending from the orifice into the secondary air passage, the needle being axially moveable to provide variability of the orifice and control of the fuel flow; a control device for directly linking or controlling the position of the needle to the position of the adjustable throttle in the primary air passage for adjustment of the orifice of the nozzle. The arrangement is such that the fuel flow from the nozzle is matched to the position of the adjustable throttle and the fuel flowing from the orifice towards the small diameter end of the needle mixes with air flowing through the secondary passage prior to mixing with the air flowing through the primary air passage.