Exhaust Emission Control System; Secondary Air Supply System - Honda 2003 NPS50 Ruckus Service Manual

EXHAUST EMISSION CONTROL SYSTEM ('03

SECONDARY AIR SUPPLY SYSTEM

The exhaust emission control system consists of a secondary air supply system which introduces filtered air into the
exhaust gases in the exhaust port. Fresh air is drawn into the exhaust port whenever there is a negative pressure pulse in
the exhaust system. This charge of fresh air promotes burning of the unburned exhaust gases and changes a considerable
amount of hydrocarbons and carbon monoxide into relatively harmless carbon dioxide and water vapor.
This model has a pulse secondary air injection (PAIR) control valve. A PAIR check valve prevents reverse air flow through
the system. The PAIR control valve reacts to high intake manifold vacuum and will cut off the supply of fresh air during
engine deceleration, thereby preventing afterburn in the exhaust system.
No adjustment to the PAIR system should be made, although periodic inspection of the components is recommended.
VACUUM HOSE
GENERAL INFORMATION
'05 model)
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AIR CLEANER
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...
FRESH AIR
EXHAUST GAS
1 -35