Yamaha YZF-R1P 2001-2003, Service Manual

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FI
AIR INDUCTION SYSTEM
EAS00507
AIR INDUCTION SYSTEM
AIR INDUCTION
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
(1,100 to 1,300 °F).
EAS00508
AIR CUT-OFF VALVE
The air cut-off valve is controlled by the signals
from the ECU in accordance with the combus-
tion conditions. Ordinarily, the air cut-off valve
opens to allow the air to flow during idle and
closes to cut-off the flow when the motorcycle
is being driven. However, if the coolant tem-
perature is below the specified value, the air
cut-off valve remains open and allows the air
to flow into the exhaust pipe until the tempera-
ture becomes higher than the specified value.
È
From the air cleaner
É
To the cylinder head