Abstract: A gasoline fume generator and mixer for use with an internal combustion engine is disclosed. Liquid fuel is fed through a metering valve and flows over a hot heat exchange unit which is maintained at a temperature above 200.degree. F. by flow of engine coolant therethrough. The fumes generated by contact of the fuel with the heat exchange unit are mixed with air which is pulled into the generator tank by vacuum. This fume and air mixture is pulled out of the tank and into the carburetor to operate the engine in a conventional manner. A liquid level float actuated flow control device and a flap valve are provided to control the operation of the generator and a clean out plug is provided to allow periodic removal of portions of the liquid fuel which are not turned into fumes by the generator. An optional electric resistance heater is used to elevate the temperature of the liquid fuel entering the generator and mixer when needed, such as in cold weather and quick starts.