This system supplies air for the further combustion of unburned gases in the thermal reactor (California only) or exhaust manifold and consists of a reed valve, air hoses, and air passages built into the cylinder head.
The reed valve is operated by exhaust pulsations in the exhaust manifold. It draws fresh air through the air cleaner and supplies it to the exhaust ports.
Check for damage to the air hoses and air pipes. Make sure the air passages are open in the head.