Air Induction System; Air Injection; Air Cut-Off Valve - Yamaha YP400T Service Manual

FI

AIR INDUCTION SYSTEM

EAS00507
AIR INDUCTION SYSTEM

AIR INJECTION

The air induction system burns unburned
exhaust gases by injecting fresh air (second-
ary air) into the exhaust port, reducing the
emission of hydrocarbons.
When there is negative pressure at the
exhaust port, the reed valve opens, allowing
secondary air to flow into the exhaust port. The
required temperature for burning the unburned
exhaust gases is approximately 600 to 700 °C
(1,112 to 1,292 °F).
EAS00917

AIR CUT-OFF VALVE

È
The air cut-off valve prevents air backflow from
the exhaust port of the cylinder head to the air
filter.
È From the air filter
É To the cylinder head
É
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