14. Emission Control System
14-7
1. Warm-up test:
y Start engine.
y Remove the air injection filter.
y Check the air inlet if there is air-sucking sounds during idling (should hear Bo-Bo-Bo sound).
y If no sound is heard, remove air cut-off valve, and connect a vacuum meter to air pipe to check for
leakage.
y If there is no vacuum, replace reed valve and test again.
y If there is no vacuum, check the air pipe for leakage, plugged or loose.
Secondary air inject
filter
Air injection cut
valve
Reed valve
Cylinder head
Engine
Carburetor
Exhaust muffler
Air filter
Vacuum gauge
Carburetor
Air filter
Exhaust muffler
Engine
Reed valve
Air injection cut valve
Secondary air inject
filter
Air inlet
Cylinder head
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