Honda NSS250 2007, Owner'S Manual, Page: 202 / 233

193
Emission Control Systems
Technical Information
Exhaust Emission Control System
Secondary Air Injection System
Evaporative Emission Control System
Ignition Timing Control System
Oxidation Catalytic Converter
The exhaust emission control system
includes a secondary air supply system,
and an oxidation catalytic converter.
No adjustment to these systems should be
made although periodic inspection of the
components is recommended.
The secondary air injection system
introduces filtered air into the exhaust
gases in the exhaust port. The secondary
air injection system helps improve
emission performance.
The oxidation catalytic converter is in the
exhaust system. Through chemical
reactions, they convert HC and CO in the
engine’s exhaust to carbon dioxide (CO )
and water vapor.
This scooter complies with the
requirements of the California Air
Resources Board (CARB) evaporative
emission regulations. Fuel vapor from the
fuel tank and carburetor is directed into
the charcoal canister and air cleaner where
it is adsorbed and stored while the engine
is stopped. When the engine is running
and the purge control diaphragm valve is
open, fuel vapor in the charcoal canister
and air cleaner is drawn into the engine
through the carburetor.
The system constantly adjusts the ignition
timing, reducing the amount of HC, CO
and NOx produced.
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