19. EVAPORATIVE/EXHAUST EMISSION CONTROL SYSTEM K-PIPE 50 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 Prevent exhaust Air Injection re-burned to reduce CO. When the throttle valve muffler noise and Cut-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 1