Yamaha XT660R S Service Manual

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GEN
INFO
FEATURES
EAS00897
FI SYSTEM
The fuel pump delivers fuel to the injector via the fuel filter. The pressure regulator maintains the
fuel pressure that is applied to the injector at 324 kPa (3.24 kg/cm
2
, 46.1 psi) higher than the intake
manifold pressure. Accordingly, when the energizing signal from the ECU energizes the injector, the
fuel passage opens, causing the fuel to be injected into the intake manifold only during the time the
passage remains open. Therefore, the longer the length of time the injector is energized (injection
duration), the greater the volume of fuel that is supplied. Conversely, the shorter the length of time
the injector is energized (injection duration), the lesser the volume of fuel that is supplied.
The injection duration and the injection timing are controlled by the ECU. Signals that are input from
the throttle position sensor, crankshaft position sensor, intake air pressure sensor, intake air tem-
perature sensor, and coolant temperature sensor enable the ECU to determine the injection dura-
tion. The injection timing is determined through the signal from the crankshaft position sensor. As a
result, the volume of fuel that is required by the engine can be supplied at all times in accordance
with the driving conditions.
1
Fuel pump
2
Pressure regulator
3
Fuel injector
4
Throttle body
5
Intake air temperature
sensor
6
Throttle position sen-
sor
7
Intake air pressure
sensor
8
ECU
9
Coolant temperature
sensor
0
Crankshaft position
sensor
È
Fuel system
É
Air system
Ê
Control system
0
9
6
4
5
7
8
1
3
2
#1
È
É
Ê
Illustration is for reference only.

Yamaha XT660R S Specifications

General

Displacement	660 cc
Bore x Stroke	100.0 mm x 84.0 mm
Compression Ratio	10.0:1
Fuel System	Fuel Injection
Ignition System	TCI
Starter System	Electric
Transmission System	5-speed
Final Drive	Chain
Front Suspension System	Telescopic forks
Front Tyre	90/90-21 M/C 54S
Rear Tyre	130/80-17 M/C 65S
Overall Width	865 mm
Overall Height	1, 230 mm
Seat Height	865 mm
Wheelbase	1, 505 mm
Wet Weight	181 kg
Fuel Tank Capacity	15 litres
Oil Tank Capacity	2.9 litres
Engine Type	Liquid-cooled, 4-stroke, single cylinder, SOHC
Maximum Power	48hp (35kW) @ 6, 000rpm
Frame	Steel diamond
Rear Suspension System	Swingarm, (link suspension)
Front Brake	Single 298mm disc, 2-piston caliper
Rear Brake	Single Disc, 245 mm