2007 YAMAHA YFZ450 service

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6. Turn in the adjusting bolt at the rear brake cal-
iper until it feels tight, then turn it out 1/8 turn
and tighten its locknut to the specified torque.
CAUTION:

ECB00520
When tightening the locknut, hold the adjust-
ing bolt with a wrench so that it does not turn
together with the locknut.
WARNING

EWB02090
Operating with improperly serviced or adjust-
ed brakes could cause the brakes to malfunc-
tion, resulting in reduced braking
performance. This could increase the chance
of a collision or accident. After adjusting the
parking brake free play, block the rear of the
ATV off the ground and spin the rear wheels.
Check to make sure there is no brake drag. If
brake drag is noticed, perform the adjustment
again.
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Brake light switches
The operation of the brake light switches must be
checked and, if necessary, adjusted at the inter-
vals specified in the periodic maintenance and lu-
brication chart.
The brake light switch for the brake pedal can be
adjusted as follows, but the other brake light
switches should be adjusted by a Yamaha dealer.
NOTE:

The brake light switch is properly adjusted when
the brake light comes on just before braking takes
effect.
Turn the adjusting nut while holding the brake light
switch in place. To make the brake light come on
earlier, turn the adjusting nut in direction (a). To
make the brake light come on later, turn the adjust-
ing nut in direction (b). Tightening torque:
Locknut (rear brake caliper):
16 Nm (1.6 m·kgf, 12 ft·lbf)

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CAUTION:

ECB00541
Improper drive chain slack will overload the en-
gine as well as other vital parts of the ATV and
can lead to drive chain slippage or breakage.
To prevent this from occurring, keep the drive
chain slack within the specified limits.
5. Pull the rod out, and then tighten the rear axle
pinch bolts to the specified torque in the order
shown.
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Lubricating the drive chain
The drive chain must be cleaned and lubricated at
the intervals specified in the periodic maintenance
and lubrication chart, otherwise it will quickly wear
out, especially when riding in dusty or wet areas.
Service the drive chain as follows.
CAUTION:

ECB00560
The drive chain must be lubricated after wash-
ing the ATV or riding in the rain.
1. Clean the drive chain with kerosene and a Tightening torque:
Rear axle pinch bolt:
21 Nm (2.1 m·kgf, 15.2 ft·lbf)
3124

1. O-rings
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Front

2. Lower the ATV to the ground.
3. Tighten the wheel nuts to the specified
torques.
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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)

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SPECIFICATIONS
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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)
Engine:
Engine type:
Liquid cooled 4-stroke, DOHC
Cylinder arrangement:
Forward-inclined single cylinder
Displacement:
449.0 cm
3

(27.40 cu.in)
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:
SAE5W30 or SAE10W30 or SAE10W40 or SAE15W40
or SAE20W40 or SAE20W50
Recommended engine oil grade:
API service SE, SF, SG type or higher
-20˚-10˚0˚
10˚20˚30˚40˚50˚C
10W/30
15W/4020W/4020W/50
10W/40
5W/30