Sym PA12B Service Manual page 225

14. Emission Control System
3. Service Points/Trouble Diagnosis:
Diesel
a. Malfunction of air inject cut valve (AICV).
b. System hose leakage.
c. abnormal ignition timing.
d. lean mixture gas.
e. abnormal fuel supply.
Rich Exhaust Gas:
a. plugged air-jet by dirty carburetor.
b. poor adjustment of air adjustment screw.
c. poor reed valve.
d. System hose leakage or plugged.
Noise:
a. System hose leakage.
b. Loosen secondary air injection filter.
c. Loosen secondary air injection filter hose.
4. AI System Service methods:
a. Visual check:
Check reed valve, air cut-off valve, secondary air cleaner for outside damages.
Check metal pipes and hoses for breakage and cracks.
b. Leak test:
Secondary air injection filter
(A.I.A.C.)
Pressure source
Plug the hose leading to reed valve.
Remove the hose of connection to air injection cut valve. Connect a T-type hose connector,
pressure gauge and pressure source as shown above.
With engine stopped, apply 1.0kg/cm2 pressure to inlet and then plug it. There should be no
leakage.
14-6
To this chapter contents
Pressure gauge
To engine vacuum
source
To reed valve
(R/V)
Air inject cut valve (AICV)