Deceleration Valve

Assembly is connected to intake manifold. Valve body contains a spring loaded diaphragm which is held in place by the bottom cover. Diaphragm is subjected to manifold vacuum on top side and to atmospheric pressure on underside (by a bleed hole in cover). During periods of deceleration, intake manifold vacuum is sufficient for diaphragm to overcome spring loading and lift deceleration valve off its seat. With valve open, vacuum draws a metered amount of air and fuel from fuel pick up tube and air bleed, which flows from outlet tube through deceleration valve and into manifold. This additional air/fuel mixture, coupled with other engine modifications, provides improved combustion. The air/fuel supply needed for combustion is feed to engine through a hose which connects deceleration valve to deceleration section of the carburetor.