Abstract: A device which, when an engine is not yet running at a steady temperature, provides for the regulation of fuel-air ratio as a function of the engine temperature but independently of the flow rate of the air aspirated by the engine, by means of additional throttling means, upstream of the main throttling means. The additional throttling means are controlled by a device sensitive to the temperature of the running engine, so as to correspondingly adjust the density of the air aspirated by the engine only as a function of the engine temperature.

Abstract: A fuel feeding system for internal combustion engines, of the type comprising a carburettor with a throttle controlling the main flow of fuel-air mixture to the cylinders, the carburettor further comprising a pre-mixing chamber for the air-fuel mixture, which communicates with the engine intake duct by means of ports located both upstream and downstream of the throttle in its closed condition, said pre-mixing chamber feeding also with air-fuel mixture a secondary chamber, communicating both with the atmospheric air and with the intake duct downstream of the said throttle, whereby the fuel-air ratio is kept constant both at idling and at low RPM of the engine.