YAMAHA YFZ450 2009 Owners Manual

8-41
1
2
3
4
5
6
78
9
10
11

EBU26862
Drive chain slack
The drive chain slack should be checked before
each ride and adjusted if necessary.
To check the drive chain slack
1. Place the ATV on a level surface.
TIP

When checking and adjusting the drive chain
slack, there should be no weight on the ATV and
all tires must be touching the ground.
2. Move the ATV back and forth to locate the
tightest portion of the drive chain, and then
measure the drive chain slack as shown.3. If the drive chain slack is incorrect, adjust it as
follows.
To adjust the drive chain slack
1. Place the ATV on a level surface.
2. Loosen the rear axle pinch bolts.
3. Insert a rod of a diameter of 8 mm (0.3 in) and
a length of 10 cm (4 in) into one of the holes in
the drive chain tensioner as shown. Drive chain slack:
25.0–35.0 mm (0.98–1.38 in)
1. Drive chain slack
1

8-42
1
2
3
4
5
6
78
9
10
11
TIP

A rod can be obtained at a Yamaha dealer to make
this adjustment.
4. Shift the transmission into neutral.
5. To tighten the drive chain, push the ATV back-
ward. To loosen the drive chain, push the ATV
forward.
NOTICE

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.
6. Pull the rod out, and then tighten the rear axle
pinch bolts to the specified torque in the order
shown.
1. Rear wheel axle pinch bolt
2. Rod
3. Drive chain tensioner
4. Hole
3
4
2
1
1

Tightening torque:
Rear axle pinch bolt:
21 Nm (2.1 m·kgf, 15.2 ft·lbf)
3124

8-43
1
2
3
4
5
6
78
9
10
11

EBU24880
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.
NOTICE

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 asmall soft brush.
NOTICE

ECB00570
To prevent damaging the O-rings, do not clean
the drive chain with steam cleaners, high-pres-
sure washers or inappropriate solvents.
2. Wipe the drive chain dry.
3. Thoroughly lubricate the drive chain with a
special O-ring chain lubricant.
NOTICE

ECB00580
Do not use engine oil or any other lubricants
for the drive chain, as they may contain sub-
stances that could damage the O-rings.
EBU24900
Checking and lubricating the cables
The operation and the condition of all control ca-
bles should be checked before each ride, and the
cables and cable ends should be lubricated if nec-
essary. If a cable is damaged or does not move
smoothly, have a Yamaha dealer check or replace
it.
1. O-rings
1

Recommended lubricant:
Engine oil

8-44
1
2
3
4
5
6
78
9
10
11
WARNING

EWB02130
Inspect cables frequently and replace if dam-
aged. Corrosion can result when the cable
sheaths become damaged, and cables can
also become frayed or kinked, which could re-
strict the operation of controls and lead to an
accident or injury.
EBU24922
Checking and lubricating the brake and
clutch levers
The operation of the brake and clutch levers
should be checked before each ride, and the lever
pivots should be lubricated if necessary.
Brake lever
Clutch lever
Recommended lubricants:
Brake lever:
Silicone grease
Clutch lever:
Lithium-soap-based grease

8-45
1
2
3
4
5
6
78
9
10
11

EBU24931
Checking and lubricating the brake and
shift pedals
The operation of the brake and shift pedals should
be checked before each ride, and the pedal pivots
should be lubricated if necessary.
Brake pedal
EBU24962
Checking the wheel hub bearings
The front and rear wheel hub bearings must be
checked at the intervals specified in the periodic
maintenance and lubrication chart. If there is play
in a wheel hub or if a wheel does not turn smoothly,
have a Yamaha dealer check the wheel hub bear-
ings.
EBU24994
Lubricating the swingarm pivots
The swingarm pivots must be lubricated at the in-
tervals specified in the periodic maintenance and
lubrication chart. Recommended lubricants:
Brake pedal:
Silicone grease
Shift pedal:
Lithium-soap-based grease (all-purpose
grease)
Recommended lubricant:
Lithium-soap-based grease

8-46
1
2
3
4
5
6
78
9
10
11

EBU25032
Lubricating the upper and lower arm
pivots
The upper and lower arm pivots must be lubricated
at the intervals specified in the periodic mainte-
nance and lubrication chart.
Lubricate the pivoting points using a grease gun.
Left side
Recommended lubricant:
Lithium-soap-based grease
1. Upper grease nipple
2. Lower grease nipple
21

8-47
1
2
3
4
5
6
78
9
10
11
Right side

EBU25224
Battery
This model is equipped with a VRLA (Valve Regu-
lated Lead Acid) battery. There is no need to check
the electrolyte or to add distilled water. However,
the battery lead connections need to be checked
and, if necessary, tightened.
NOTICE

ECB00620
Never attempt to remove the battery cell seals,
as this would permanently damage the battery.WARNING

EWB02160
Battery electrolyte is poisonous and danger-
ous, as it contains sulfuric acid, which can
cause severe burns. Avoid contact with skin,
eyes or clothing. Always shield your eyes
when working near batteries.
Antidote:
EXTERNAL: Flush with water.
INTERNAL: Drink large quantities of water or
milk. Follow with milk of magnesia, beaten egg
or vegetable oil. Call a physician immediately.
EYES: Flush with water for 15 minutes and get
prompt medical attention.
Batteries produce explosive gases. Keep
sparks, flame, cigarettes or other sources of ig-
nition away. Ventilate when charging or using
in an enclosed space.
KEEP OUT OF REACH OF CHILDREN.
To remove the battery
1. Remove the seat. (See page 4-11.)
2. Unhook the band securing the owner’s tool kit,
and then remove the battery holding plate by
removing the bolts.
3. Disconnect the negative battery lead first,
1. Upper grease nipple
2. Lower grease nipple
2 1

8-48
1
2
3
4
5
6
78
9
10
11

then the positive battery lead by removing
their bolt.
4. Pull the battery out of its compartment.
To charge the battery
Have a Yamaha dealer charge the battery as soon
as possible if it seems to have discharged. Keep in
mind that the battery tends to discharge more
quickly if the ATV is equipped with optional electri-cal accessories.
To store the battery


If the ATV will not be used for more than one
month, remove the battery, fully charge it, and
then place it in a cool, dry place.

If the battery will be stored for more than two
months, check it at least once a month and fully
charge it if necessary.
To install the battery
TIP

Be sure the battery is fully charged.
1. Place the battery in its compartment.
2. Connect the positive battery lead first, then
connect the negative battery lead by installing
their bolt.
3. Install the battery holding plate by installing
the bolts, and then hook the band to secure
the owner’s tool kit.
4. Install the seat. (See page 4-11.)
1. Bolt
2. Negative battery lead (black)
3. Positive battery lead (red)
4. Battery
1
1
2 3
4

8-49
1
2
3
4
5
6
78
9
10
11
NOTICE

ECB00631

Always keep the battery charged. Storing a
discharged battery can cause permanent
battery damage.

To charge a VRLA (Valve Regulated Lead Ac-
id) battery, a special constant-voltage bat-
tery charger is required. Using a
conventional battery charger will damage
the battery. If you do not have access to a
constant-voltage battery charger, have a
Yamaha dealer charge your battery.
EBU25262
Replacing the fuse
The fuse holder is located on the right side of the
ATV.
If the fuse is blown, replace it as follows.
1. Turn the key to “OFF” and turn off all electrical
circuits.
1. Negative battery lead (black)
2. Positive battery lead (red)
2
1

1. Fuse
2. Spare fuse
1
2

8-50
1
2
3
4
5
6
78
9
10
11
NOTICE

ECB00640
To prevent accidental short-circuiting, turn off
the main switch when checking or replacing a
fuse.
2. Remove the blown fuse, and then install a
new fuse of the specified amperage.
WARNING

EWB02171
Always use a fuse of the specified rating, and
never use a substitute object in place of the
proper fuse. An improper fuse or a substitute
object can cause damage to the electrical sys-
tem, which could lead to a fire.
3. Turn the key to “ON” and turn on the electrical
circuits to check if the devices operate.
4. If the fuse immediately blows again, have a
Yamaha dealer check the electrical system.
EBU25440
Replacing a headlight bulb
If a headlight bulb burns out, replace it as follows.
1. Remove the headlight unit by removing the
bolts.
2. Disconnect the headlight coupler.
3. Remove the headlight bulb holder cover. Specified fuse:
15.0 A
1. Headlight assembly
2. Bolt
21