2012 YAMAHA YFZ450R light

8-8
8
EBU29430TIP
Some maintenance items need more frequent service if you are riding in unusually wet, dusty, sandy or
muddy areas, or at full-throttle.
Replace the fuel hose every five years and if cracked or damaged.
Hydraulic brake service
Regularly check and, if necessary, correct the brake fluid level.
 Every two years replace the internal components of the brake master cylinders and calipers, and
change the brake fluid.
 Replace the brake hoses every four years and if cracked or damaged.23 *Throttle lever 
Check operation.
 Check throttle lever free play, and adjust if neces-
sary.
 Lubricate cable and lever housing. √√√√√
24 *Front and rear brake
switches

Check operation and correct if necessary. √√√√√
25 *Lights and switches 
Check operation and correct if necessary.
 Adjust headlight beams. √√√√√
NO. ITEM
CHECK OR MAINTENANCE
JOB INITIAL EVERY
Whichev- er comes first month136612
km
(mi) 320
(200) 1300
(800) 2500
(1600) 2500
(1600) 5000
(3200)
hours 20 80 160 160 320U18P66E0.book Page 8 Monday, May 16, 2011 4:23 PM

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8
To install the cowling
1. Place the cowling in the original position, and
then tighten the quick fasteners.
2. Install panels C, B and A.EBU29441Checking the spark plug The spark plug is an important engine component,
which should be checked periodically, preferably
by a Yamaha dealer. Since heat and deposits will
cause any spark plug to slowly erode, the spark
plug should be removed and checked in accor-
dance with the periodic maintenance and lubrica-
tion chart. In addition, the condition of the spark
plug can reveal the condition of the engine.
The porcelain insulator around the center elec-
trode of the spark plug should be a medium-to-light
tan (the ideal color when the vehicle is ridden nor-
mally). If the spark plug shows a distinctly different
color, the engine could be operating improperly.
Do not attempt to diagnose such problems your-
self. Instead, have a Yamaha dealer check the ve-
hicle.
If the spark plug shows signs of electrode erosion
and excessive carbon or other deposits, it should
be replaced.
1. Quick fastener
1. Quick fastener
11
1
1
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82. Remove the tailpipe by pulling it out of the
muffler.
3. Tap the tailpipe lightly, and then use a wire brush to remove any carbon deposits from the
spark arrester portion of the tailpipe and inside
of the tailpipe housing. 4. Insert the tailpipe into the muffler and align the
bolt holes.
5. Install the bolt and tighten it to the specified torque.
6. Remove the purging bolt and the gasket.
1. Tailpipe bolt
2. Tailpipe
1
2
1. Tailpipe
2. Spark arresterTightening torque: Tailpipe bolt:8 Nm (0.8 m ·kgf, 5.8 ft· lbf)
1
2
U18P66E0.book Page 28 Monday, May 16, 2011 4:23 PM

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8hold the adjusting bolt with a wrench so
that it does not turn together with the lock-
nut.
[ECB00521]
WARNING
EWB02090Operating 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.EBU24743Brake light switches The brake light, which is activated by the brake
pedal and brake lever, should come on just before
braking takes effect. The brake light switch for the brake pedal can be
adjusted as follows, but the front brake light switch
should be adjusted by a Yamaha dealer.
Turn the rear brake light switch 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 adjusting nut in direction (b).
EBU30152Adjusting the clutch lever free play The clutch lever free play must be checked and, if
necessary, adjusted at the intervals specified in the
periodic maintenance and lubrication chart.
Tightening torque:
Locknut (rear brake caliper):16 Nm (1.6 m ·kgf, 12 ft· lbf)1. Rear brake light switch
2. Rear brake light switch adjusting nut
1
2(a) (b)
U18P66E0.book Page 36 Monday, May 16, 2011 4:23 PM

8-48
82. Remove the blown fuse, and then install a
new fuse of the specified amperage.
WARNING! Always use a fuse of the spec-
ified rating, and never use a substitute ob-
ject in place of the proper fuse. An
improper fuse or a substitute object can
cause damage to the electrical system,
which could lead to a fire.
[EWB02172]
3. Turn the key to “” (on) and turn on the elec-
trical circuits to check if the devices operate.
4. If the fuse immediately blows again, have a Yamaha dealer check the electrical system.EBU30161Replacing a headlight bulb If a headlight bulb burns out, replace it as follows.1. Remove the headlight unit by removing the bolt, and then pulling the headlight unit out-
ward as shown. 2. Remove the headlight bulb holder cover.
Specified fuse:
20.0 A
1. Headlight unit
2. Bolt
1. Headlight bulb holder cover
1
2
1
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8
3. Remove the headlight bulb holder by pushing
it in and turning it counterclockwise, and then
remove the burnt-out bulb.
4. Place a new headlight bulb into position. NOTICE: Do not touch the glass part of the
headlight bulb to keep it free from oil, oth-
erwise the transparency of the glass, the
luminosity of the bulb, and the bulb life will
be adversely affected. Thoroughly clean
off any dirt and fingerprints on the head-
light bulb using a cloth moistened with al-
cohol or thinner.
[ECB00651]
5. Install the headlight bulb holder by pushing it in and turning it clockwise.
6. Install the headlight bulb holder cover.
7. Place the headlight unit in the original posi- tion, and then install the bolt.
1. Headlight bulb holder
1
1. Do not touch the glass part of the bulb.
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88. Adjust the headlight beam if necessary.
EBU25561Adjusting a headlight beam NOTICEECB00690It is advisable to have a Yamaha dealer make
this adjustment.To raise a headlight beam, turn the headlight beam
adjusting bolt in direction (a).
To lower a headlight beam, turn the adjusting bolt
in direction (b).
EBU26920Tail/brake light This model is equipped with an LED type of
tail/brake light.
If the tail/brake light does not come on, have a
Yamaha dealer check it.EBU25651Removing a wheel 1. Place the ATV on a level surface.
2. Loosen the wheel nuts.1. Headlight beam adjusting bolt
1
(a)
(b)
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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