Operation

OPERATION




SECONDARY AIR PUMP
The secondary air pump compresses the air drawn in by the DC motor, and supplies this compressed air to the secondary air combination valve. There is a filter at the inlet of the secondary air pump to prevent drawing in dust and foreign objects.




SECONDARY AIR COMBINATION VALVE
The secondary air combination valve consists of an air valve, a reed valve that prevents the reverse flow of exhaust gas, and a solenoid for opening/closing the air valve. Compressed air whose flow is controlled by the secondary air combination valve is supplied to the cylinder head through a pipe.
One of the secondary air combination valves is equipped with a pressure sensor for malfunction diagnosis.




CYLINDER HEAD
Inside the cylinder head are air passages as shown in the diagram. The compressed air supplied from the secondary air combination valve travels through these air passages to be sprayed on the back face of the exhaust valve.