An oil burner system in which a fuel oil pump and the air blower are independently driven by a common motor having a single stator and two independently driven rotors. One rotor is connected to the pump and the other to the air blower so that the inertia of the pump drive is reduced and it comes to a stop quicker. The rotor for driving the pump is disposed in an oil-filled compartment so that it is damped. The system is provided with a bypass valve connecting the discharge side of the pump with its suction controlled by the motor shaft which is biased to open the bypass valve when the motor is in a deenergized condition. When the motor is energized the shaft is attracted axially electromagnetically and it closes the bypass valve. When the motor is deenergized it opens the bypass valve, the pump stops relatively quickly and the blower continues to blow air to ensure burning of all oil supplied from the burner and avoid coking on the burner and elsewhere.