Abstract: A fuel-vapor emission control system has a canister having a vacuum operated purge control valve, communicated with a float chamber of a carburetor and a fuel tank for purging fuel-vapor. A vacuum chamber of the vacuum operated purge control valve is communicated with a port provided in the carburetor so as to apply manifold vacuum to the vacuum chamber at partial-throttle operation. Parallel purge lines are provided for communicating the canister with an intake manifold of the engine. A solenoid operated valve is provided in one of the purge lines for controlling the purging of the fuel-vapor. The solenoid operated valve is opened for the purging by a signal from a vehicle or engine speed sensor under such conditions that the engine does not stall.