Anti-Afterburn Valve

During periods of deceleration and when shifting gears, intake manifold vacuum causes valve to open. With valve open, fresh air from carburetor air cleaner passes through valve and enters the intake manifold to correct the overrich mixture caused by sudden throttle closure. During normal running conditions, solenoid is de-energized and valve is closed. When engine speed exceeds 4000±200 RPM, control box energizes solenoid and valve is opened allowing fresh air to enter intake manifold to prevent afterburning during deceleration at high engine speeds. When the engine is switched off, solenoid opens vacuum line and due to the resulting pressure difference between air and vacuum chambers, valve opens and directs air into intake manifold to prevent afterburn. A metering orifice in valve diaphragm controls duration of valve opening.