Abstract: A mixing and distributing device for gasoline and oil comprises an oil inlet, a duct for gasoline under pressure and a delivery duct. A first vertical cylinder having a first piston is fed from the top with oil and gasoline through a slide valve. A second vertical cylinder, which is located inside the first cylinder and under the first piston, has a second oil piston sliding therein. When the valve is in a first position, gasoline under pressure is fed to the first cylinder thereby urging the first piston downward against a biasing spring to move the second piston downward through abutments on the interior of the first piston. This causes a metered supply of oil to be fed to the top of the first cylinder so as to mix with the pressurized gasoline. A second position of the valve terminates the supply of oil and gasoline, and allows the mixture to be expelled by the first cylinder piston under the effect of the biasing spring through the valve and the delivery duct.