2016 YAMAHA YFM90 Owners Manual

8-26
8
To adjust the drive chain slack
1. Loosen the bolts and nuts. 2. Loosen the rear brake lever free play adjust-
ing nut.
3. Loosen the locknut.
1. Bolt
1. Nut
1
1
1. Rear brake lever free play adjusting nut
1
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8-28
8
1. Clean the drive chain with kerosene and a
small soft brush. NOTICE: To prevent dam-
aging the O-rings, do not clean the drive
chain with steam cleaners, high-pressure
washers or inappropriate solvents.
[ECB00572]
2. Wipe the drive chain dry.
3. Thoroughly lubricate the drive chain with a special O-ring chain lubricant. NOTICE: Do
not use engine oil or any other lubricants
for the drive chain, as they may contain
substances that could damage the O-
rings.
[ECB00582] EBU24905
Checking and lubricating the cablesThe 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.
WARNING
EWB02582
Inspect cables frequently and replace if
damaged. Corrosion can result when the ca-
ble sheaths become damaged, and cables
can also become frayed or kinked, which
could restrict the operation of controls and
lead to an accident or injury.
 Always make sure all control cables work
smoothly before you begin riding in cold
weather. If the control cables are frozen or
1. O-ring
1
1
Recommended lubricant:
Yamaha cable lubricant or other suitable cable lubricant
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8-29
8do not work smoothly, you could be unable
to control the ATV, which could lead to an
accident or collision.
EBU28703Checking and lubricating the front and
rear brake leversThe operation of the front and rear brake levers
should be checked before each ride, and the lever
pivots should be lubricated if necessary.
Front brake lever
Rear brake lever
EBU24964Checking the wheel hub bearingsThe 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 smooth-
ly, have a Yamaha dealer check the wheel hub
bearings.
Recommended lubricant:
Lithium-soap-based grease
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8
EBU28824Lubricating the front knuckle pivotsThe front knuckle pivots must be lubricated at the
intervals specified in the periodic maintenance
and lubrication chart.TIPFor parts equipped with a grease nipple, use a
grease gun.
EBU25094Lubricating the steering shaftThe steering shaft must be lubricated by a
Yamaha dealer at the intervals specified in the pe- riodic maintenance and lubrication chart.TIPFor parts equipped with a grease nipple, use a
grease gun.
Recommended lubricant: Lithium-soap-based grease
1. Grease nippleRecommended lubricant:Lithium-soap-based grease
1
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8-31
8
EBU34020BatteryThe battery is located under the seat. (See page
4-12.)
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.
WARNING
EWB02161Battery 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
ignition away. Ventilate when charging or using
in an enclosed space.KEEP OUT OF REACH OF CHILDREN.
NOTICEECB00621Never attempt to remove the battery cell seals,
as this would permanently damage the battery. To remove the battery
1. Remove the seat. (See page 4-12.)
2. Unhook the battery band.1. Positive battery lead (red)
2. Negative battery lead (black)
3. Battery
4. Battery band
3
4
2
1
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8
3. Disconnect the negative battery lead first,
then the positive battery lead by removing
their bolt. NOTICE: When removing the bat-
tery, the main switch must be off, and the
negative lead must be disconnected be-
fore the positive lead.
[ECB01002]
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 elec-
trical accessories.NOTICEECB00932To charge a VRLA (Valve Regulated Lead Acid)
battery, a special (constant-voltage) battery
charger is required. Using a conventional bat-
tery charger will damage the battery. 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.
NOTICEECB00941Always keep the battery charged. Storing a
discharged battery can cause permanent bat-
tery damage. To install the batteryTIPBe 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. NOTICE: When installing the bat-
tery, the main switch must be off, and the
positive lead must be connected before
the negative lead.
[ECB01111]
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83. Hook the battery band.
4. Install the seat. (See page 4-12.)
EBU25244Replacing the fuseThe fuse holder is located under the seat. (See
page 4-12.)
If the fuse is blown, replace it as follows.
1. Turn the key to “OFF” and turn off all electrical circuits.NOTICEECB00641To prevent accidental short-circuiting, turn off
the main switch when checking or replacing a
fuse.
1. Positive battery lead (red)
2. Negative battery lead (black)
2
1
1. Fuse
2. Spare fuse
2 1
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