compression ratio YAMAHA YFZ450 2009 Owners Manual

4-16
1
2
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NOTICE

ECB00090
Never turn an adjusting mechanism beyond
the minimum and maximum settings.
TIP

Although the total number of clicks of a damping
force adjusting mechanism may not exactly match
the above specifications due to small differences in
production, the actual number of clicks always rep-
resents the entire adjusting range. To obtain a pre-
cise adjustment, it would be advisable to check the
number of clicks of each damping force adjusting
mechanism and to modify the specifications as
necessary.
WARNING

EWB00420

Suspension components become hot during
operation. Never touch the compression
damping force adjusting screw, the rebound
damping force adjusting screw or the oil res-
ervoir with your bare hand or skin until sus-
pension components have cooled.

Always adjust the shock absorber assem-
blies on the left and right side to the same
1. Compression damping force adjusting screw (for slow
compression damping)
Compression damping setting (for slow com-
pression damping):
Minimum (soft):
20 click(s) in direction (b)*
Standard:
10 click(s) in direction (b)*
Maximum (hard):
1 click(s) in direction (b)*
* With the adjusting screw fully turned in di-
rection (a)
(b)(a)
1

4-23
1
2
34
5
6
7
8
9
10
11
NOTICE

ECB00090
Never turn an adjusting mechanism beyond
the minimum and maximum settings.
TIP

Although the total number of clicks of a damping
force adjusting mechanism may not exactly match
the above specifications due to small differences in
production, the actual number of clicks always rep-
resents the entire adjusting range. To obtain a pre-
cise adjustment, it would be advisable to check the
number of clicks of each damping force adjusting
mechanism and to modify the specifications as
necessary.
3. Install the seat.WARNING

EWB00440
Suspension components become hot during
operation. Never touch the compression
damping force adjusting screw, the rebound
damping force adjusting screw or the oil reser-
voir with your bare hand or skin until suspen-
sion components have cooled.
1. Compression damping force adjusting screw (for slow
compression damping)
Compression damping setting (for slow com-
pression damping):
Minimum (soft):
20 click(s) in direction (b)*
Standard:
11 click(s) in direction (b)*
Maximum (hard):
1 click(s) in direction (b)*
* With the adjusting screw fully turned in di-
rection (a)
(b)(a)
1

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78
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wheel.
Front
3. Lower the ATV to the ground.
4. Tighten the wheel nuts to the specified
torques.
EBU25740
Troubleshooting
Although Yamaha ATVs receive a thorough in-
spection before shipment from the factory, trouble
may occur during operation. Any problem in the fu-
el, compression, or ignition systems, for example,
can cause poor starting and loss of power.
The following troubleshooting charts represent
quick and easy procedures for checking these vital
systems yourself. However, should your ATV re-
quire any repair, take it to a Yamaha dealer, whose
skilled technicians have the necessary tools, expe-
rience, and know-how to service the ATV properly.
Use only genuine Yamaha replacement parts. Im-
itation parts may look like Yamaha parts, but they
are often inferior, have a shorter service life and
can lead to expensive repair bills.WARNING

EWB02280
Do not smoke when checking the fuel system.
Fuel can ignite or explode, causing severe inju-
ry or property damage. Make sure there are no
open flames or sparks in the area, including pi-
lot lights from water heaters or furnaces.
1. Arrow mark
Tightening torques:
Front wheel nut:
45 Nm (4.5 m·kgf, 33 ft·lbf)
Rear wheel nut:
45 Nm (4.5 m·kgf, 33 ft·lbf)

10-1
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910
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EBU25960
SPECIFICATIONS
EBU2597B
Dimensions:
Overall length:
1840 mm (72.4 in)
Overall width:
1170 mm (46.1 in)
Overall height:
1090 mm (42.9 in)
Seat height:
810 mm (31.9 in)
Wheelbase:
1280 mm (50.4 in)
Ground clearance:
255 mm (10.0 in)
Minimum turning radius:
3500 mm (138 in)
Weight:
With oil and fuel:
169.0 kg (373 lb)
Noise and vibration level:
Noise level (77/311/EEC):
84.5 dB(A)
Vibration on seat (EN1032, ISO5008):
Will not exceed 0.5 m/s
2

Vibration on handlebar (EN1032, ISO5008):
Will not exceed 2.5 m/s
2

Engine:
Engine type:
Liquid cooled 4-stroke, DOHCCylinder arrangement:
Forward-inclined single cylinder
Displacement:
449.0 cm 3
Bore
×
stroke:
95.0
×
63.4 mm (3.74
×
2.50 in)
Compression ratio:
11.40 :1
Starting system:
Electric starter
Lubrication system:
Dry sump

Engine oil:
Type:
SAE 5W-30 or SAE 10W-30 or SAE 10W-40 or SAE
15W-40 or SAE 20W-40 or SAE 20W-50
-20 -10 0
1020 304050 ˚C
SAE 15W-40
SAE 20W-40SAE 20W-50
SAE 10W-40
SAE 5W-30
SAE 10W-30