VAPOR RECOVERY SYSTEM

A system that prevents the escape of gasoline vapors from the fuel system into the atmosphere. The basic system consists of a canister filled with activated charcoal and pipes connecting the canister to the fuel tank and carburetor . Any vapor-filled air that leaves the fuel tank because of expansion passes through special emission control pipes to the canister where the vapors are "grabbed" and stored by the charcoal . Then when the engine is started, intake manifold vacuum draws fresh outside air up through an opening in the canister . This moving air pulls the fuel vapor out of the charcoal and carries it to the carburetor and into the engine. In the meantime any gasoline that evaporates from the carburetor collects in the carburetor and air cleaner . As soon as the engine starts this vapor is drawn down through the carburetor and into the engine along with the entering fuel-air mixture . Also called evaporative emission control . Also see exhaust emission controls .