3. INSPECTION/ADJUSTMENT MXU 500 IRS SECONDARY AIR SUPPLY SYSTEM Check the AICV (air injection control valve) This model is equipped with a built-in hoses between the AICV control solenoid secondary air supply system. The pulse valve and cylinder head for deterioration, secondary air supply system is located on damage or loose connections. Make sure the the cylinder head. hoses are not cracked. The secondary air supply system introduces filtered air into exhaust gases in the exhaust If the hoses show any signs of heat damage, port. The secondary air is drawn into the inspect the AICV check valve in the AICV exhaust port whenever there is negative reed valve cover damage. pressure pulse in the exhaust system. This charged secondary air promotes burning of the unburned exhaust gases and changes a considerable amount of hydrocarbons and carbon monoxide into relatively harmless carbon dioxide and water. 3-8