agility 50 3 Workshop-manual : Page 181

          18. EVAPORATIVE/EXHAUST EMISSION
    CONTROL SYSTEM

 EXHAUST EMISSION CONTROL SYSTEM
 The exhaust emission control system adopted in this model utilizes the reed valve to draw
 secondary air into the exhaust system for re-combustion by means of exhaust pulsation so as to
 minimize the exhaust emission.

 FUNCTION
        Item                 Purpose                                   Function
                                              It filters the fresh air drawn for re-burning to
 Secondary Air        Filter secondary air.   prevent dirt or dust from affecting the operation of
 Cleaner                                      the air injection cut-off valve.
                                              The air injection cut-off valve usually opens to
                                              lead air into the exhaust muffler in which air is re-
                    Prevent exhaust
 Air Injection Cut- muffler noise and         burned to reduce CO. When the throttle valve
 off Valve                                    closes suddenly, the air injection cut-off valve is
                    backfiring at sudden      actuated by vacuum to close and cut off secondary
                    deceleration.             air in order to prevent exhaust muffler backfiring
                                              due to air in the exhaust system.

                      Control the secondary Whenthe reed valve operatesis less than 50km per
                                                     the motorcycle speed
 Reed Valve                                   hour,                         to draw secondary air
                      air inlet to reduce CO. into the exhaust system for re-combustion.


 SERVICE INFORMATION
 GENERAL INSTRUCTIONS
 · During operation, be careful to avoid scalding caused by the exhaust muffler.
 · Note the locations of tubes for proper installation.
 · Replace any damaged tube with a new one.
 · Make sure to tighten the connector of each tube securely

 TOOLS                                          SPECIFICATIONS
 · Vacuum pump                                  Air injection cut-off valve actuating pressure
                                                     250mm/Hg30 liter/min.
                                                Reed valve stopper clearance6.6mm

 TROUBLESHOOTING
 High CO at idle speed                                    Exhaust muffler noise
 · Damaged or clogged reed valve                          · Faulty air injection cut-off valve
 · Damaged or clogged air injection cut-off valve         · Broken vacuum tube
 · Clogged air cleaner                                    · Faulty reed valve

 Backfiring at sudden deceleration
 · Damaged reed valve (malfunction)
 · Faulty air injection cut-off valve (unable to close)
 · Carburetor incorrectly adjusted
 · Faulty air cut-off valve
 · Leaking vacuum tube


18-1