2012 YAMAHA YFZ450R compression ratio

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4
WARNING
EWB02491
Suspension components become hot during
operation. Never touch the compression
damping force adjusting bolt and screw, the
rebound damping force adjusting screw or
the oil reservoir with your bare hand or skin
until suspension components have cooled.
Always adjust the shock absorber assem-
blies on the left and right side to the same
setting. Uneven adjustment can cause poor
handling and loss of stability, which could
lead to an accident.NOTICEECB00090Never turn an adjusting mechanism beyond
the minimum and maximum settings.TIPAlthough the total number of clicks or turns of a
damping force adjusting mechanism may not ex-
actly match the following specifications due to
small differences in production, the actual number
of clicks or turns always represents the entire ad-
justing range. To obtain a precise adjustment, itwould be advisable to check the number of clicks
or turns of each damping force adjusting mecha-
nism and to modify the specifications as neces-
sary.
Spring preload
1. Loosen the locknut.
2. Turn the spring preload adjusting nut in direc- tion (a) to increase the spring preload and
thereby harden the suspension, and in direc-
tion (b) to decrease the spring preload and
thereby soften the suspension.1. Locknut
2. Spring preload adjusting nut
3. Special wrench
(a)
(b) 2 1
3
U18P66E0.book Page 12 Monday, May 16, 2011 4:23 PM

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4
WARNING
EWB00410These shock absorber assemblies contain
highly pressurized nitrogen gas. Read and un-
derstand the following information before han-
dling the shock absorber assemblies.
Do not tamper with or attempt to open the
cylinder assemblies.
Do not subject the shock absorber assem-
blies to an open flame or other high heat
source. This may cause the unit to explode
due to excessive gas pressure.
Do not deform or damage the cylinders in
any way. Cylinder damage will result in poor
damping performance.

Do not dispose of a damaged or worn out
shock absorber assembly yourself. Take the
shock absorber assembly to a Yamaha deal-
er for any service.EBU30610Adjusting the rear shock absorber as-
sembly This shock absorber assembly is equipped with a
spring preload adjusting nut, a rebound damping
force adjusting screw, a compression damping
force adjusting bolt (for fast compression damp-
ing), and a compression damping force adjusting
screw (for slow compression damping).
WARNING
EWB02680Suspension components become hot during
operation. Never touch the compression
damping force adjusting bolt and screw, the re-
bound damping force adjusting screw or the
oil reservoir with your bare hand or skin until
the suspension components have cooled.
Compression damping setting (for slow com-
pression damping):Minimum (soft):18 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)
U18P66E0.book Page 16 Monday, May 16, 2011 4:23 PM

8-52
8
EBU25740Troubleshooting 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
EWB02280Do 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.U18P66E0.book Page 52 Monday, May 16, 2011 4:23 PM

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EBU25961
SPECIFICATIONS
Dimensions:Overall length:1795 mm (70.7 in)
Overall width: 1240 mm (48.8 in)
Overall height:
1065 mm (41.9 in)
Seat height: 810 mm (31.9 in)
Wheelbase: 1270 mm (50.0 in)
Ground clearance:
235 mm (9.3 in)
Minimum turning radius: 3600 mm (142 in)Weight:With oil and fuel:
184.0 kg (406 lb)Noise and vibration level:Noise level (77/311/EEC):YFZ450RB 85.9 dB(A)@3750 r/min (EUR)(FRA)(GBR)
YFZ450RSEB 85.9 dB(A)@3750 r/min
(EUR)(FRA)(GBR)
A-weighted sound power level: YFZ450RB 99.0 dB(A)@3750 r/min (EUR)(FRA)(GBR)
YFZ450RSEB 99.0 dB(A)@3750 r/min
(EUR)(FRA)(GBR) Vibration on seat (EN1032, ISO5008):
YFZ450RB Will not exceed 0.5 m/s ² (EUR)(FRA)(GBR)
YFZ450RSEB Will not exceed 0.5 m/s ²
(EUR)(FRA)(GBR)
Vibration on handlebar (EN1032, ISO5008): YFZ450RB Will not exceed 2.5 m/s ² (EUR)(FRA)(GBR)
YFZ450RSEB Will not exceed 2.5 m/s ²
(EUR)(FRA)(GBR)
Engine:Engine type: Liquid cooled 4-stroke, DOHC
Cylinder arrangement:
Forward-inclined single cylinder
Displacement: 449 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 sumpEngine oil:Recommended brand:YAMALUBE
U18P66E0.book Page 1 Monday, May 16, 2011 4:23 PM