YAMAHA YFM50R 2008 Owners Manual

8-20
1
2
3
4
5
6
78
9
10
11

EBU24090
Checking the front and rear brake
shoes
The front and rear brake shoes must be checked
for wear at the intervals specified in the periodic
maintenance and lubrication chart. Each brake is
provided with a wear indicator, which allows you to
check the brake shoe wear without having to dis-
assemble the brake. To check the brake shoe
wear, check the position of the wear indicator while
applying the brake. If a brake shoe has worn to the
point that the wear indicator reaches the wear limit
line or mark, have a Yamaha dealer replace the
brake shoes as a set.
Front brake
1. Wear limit line
2. Wear indicator
1
2

8-21
1
2
3
4
5
6
78
9
10
11
Rear brake

EBU24330
Adjusting the front brake lever free
play
The brake lever free play must be checked and, if
necessary, adjusted at the intervals specified in
the periodic maintenance and lubrication chart.
NOTE:

Before adjusting the brake lever free play, check
the front brake shoes for wear.The brake lever free play should measure 10.0–
12.0 mm (0.39–0.47 in) as shown. If the free play
is incorrect, adjust it as follows.
1. Loosen the upper locknut and fully turn in the
upper adjusting bolt.
2. Loosen the lower locknut.
3. Turn the lower adjusting bolt in direction (a) to
increase the free play, and in direction (b) to
decrease it.
1. Wear limit mark
2. Wear indicator
1
2

1. Brake lever free play
1

8-22
1
2
3
4
5
6
78
9
10
11

4. Tighten the lower locknut.
5. While applying the front brake, turn out the up-
per adjusting bolt until the upper and lower ca-
ble lengths are equal. The cable joint will
become vertical.6. Tighten the upper locknut.
WARNING

EWB02080
Operating with improperly serviced or adjust-
ed brakes could cause loss of braking ability,
which could lead to an accident.
After servicing:

Make sure the brakes operate smoothly and
that the free play is correct.

Make sure the brakes do not drag.
Replacement of brake components requires
professional knowledge. These procedures
1. Upper locknut
2. Upper adjusting bolt
3. Lower locknut
4. Lower adjusting bolt
1
2
4
3(a)(b)(a)
(b)

1. Cable joint
1

8-23
1
2
3
4
5
6
78
9
10
11

should be performed by a Yamaha dealer.
EBU24451
Adjusting the rear brake lever free play
The brake lever free play must be checked and, if
necessary, adjusted at the intervals specified in
the periodic maintenance and lubrication chart.
NOTE:

Before adjusting the brake lever free play, check
the rear brake shoes for wear.
The brake lever free play should measure 7.0–
10.0 mm (0.28–0.39 in) as shown. If the free play
is incorrect, adjust it as follows.
1. Loosen the locknut at the brake lever.
2. Turn the brake lever free play adjusting bolt at
the brake lever in direction (a) to increase the
free play, and in direction (b) to decrease it.
3. Tighten the locknut at the brake lever.
If the specified free play cannot be obtained,
proceed with the following steps.
4. Loosen the locknut at the brake lever.
5. Fully turn the adjusting bolt at the brake lever
in direction (a) to loosen the brake cable.
6. To increase the brake lever free play, turn the
1. Locknut
2. Brake lever free play adjusting bolt
3. Brake lever free play
312
(a)
(b)

8-24
1
2
3
4
5
6
78
9
10
11

adjusting nut on the brake cable at the rear
wheel hub in direction (a), and to decrease it,
turn the nut in direction (b).
7. Tighten the locknut at the brake lever.
NOTE:

If the specified free play cannot be obtained as de-
scribed above or if the rear brake does not operate
correctly, have a Yamaha dealer check the internal
rear brake mechanism.
WARNING
EWB02080
Operating with improperly serviced or adjust-
ed brakes could cause loss of braking ability,
which could lead to an accident.
After servicing:

Make sure the brakes operate smoothly and
that the free play is correct.

Make sure the brakes do not drag.
Replacement of brake components requires
professional knowledge. These procedures
should be performed by a Yamaha dealer.
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. Brake lever free play adjusting nut
1
(a)(b)

Recommended lubricant:
Engine oil

8-25
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.
EBU28701
Checking and lubricating the front and
rear brake levers
The operation of the front and rear brake levers
should be checked before each ride, and the lever
pivots should be lubricated if necessary.
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.
EBU28821
Lubricating the front knuckle pivots
The front knuckle pivots must be lubricated at the
intervals specified in the periodic maintenance and
lubrication chart.
Lubricate the front knuckle pivots using a grease
gun.
Recommended lubricant:
Lithium-soap-based grease (all-purpose
grease)
Recommended lubricant:
Lithium-soap-based grease (all-purpose
grease)

1. Grease nipple
1

8-26
1
2
3
4
5
6
78
9
10
11

EBU25101
Lubricating the steering shaft
The steering shaft must be lubricated at the inter-
vals specified in the periodic maintenance and lu-
brication chart.
EBU25121
Battery
A poorly maintained battery will corrode and dis-
charge quickly. The electrolyte level, battery lead
connections and breather hose routing should be
checked before each ride and at the intervals
specified in the periodic maintenance and lubrica-
tion chart.
To check the electrolyte level
1. Place the ATV on a level surface.
2. Check the electrolyte level in the battery.
NOTE:

The electrolyte should be between the minimum
and maximum level marks.
3. If the electrolyte is at or below the minimumlevel mark, add distilled water to raise it to the
maximum level mark.
CAUTION:

ECB00590
Use only distilled water, as tap water contains
minerals that are harmful to 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,
Recommended lubricant:
Lithium-soap-based grease (all-purpose
grease)
1. Maximum level mark
2. Minimum level mark
1
2

8-27
1
2
3
4
5
6
78
9
10
11

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.
4. Check and, if necessary, tighten the battery
lead connections and correct the breather
hose routing.
To store the battery
If the ATV will not be used for more than one
month, the battery will need to be removed and
stored as follows.
1. Disconnect the negative lead first and then the
positive lead.2. Remove the battery, fully charge it, and then
place it in a cool, dry place.CAUTION:

ECB00600
Do not leave or store the battery on its side.
3. If the battery will be stored for more than two
months, check the specific gravity of the elec-
trolyte at least once a month and fully charge
the battery whenever necessary.
1. Battery
2. Negative battery lead (black)
3. Positive battery lead (red)
23
1

8-28
1
2
3
4
5
6
78
9
10
11

To install the battery
NOTE:

Be sure the battery is fully charged.
1. Install the battery.
2. Connect the positive lead first, and then con-
nect the negative lead.
3. Make sure that the breather hose is properly
routed, in good condition, and not obstructed.
CAUTION:

ECB00610
If the breather hose is positioned in such a waythat the frame is exposed to electrolyte or gas
expelled from the battery, the frame could suf-
fer structural and external damages.
EBU25242
Replacing the fuse
The fuse holder is located under the seat. (See
page 4-11.)
If the fuse is blown, replace it as follows.
1. Turn the key to “OFF” and turn off all electrical
circuits.
1. Battery
2. Battery breather hose
1
2

1. Fuse
2. Spare fuse
1
2

8-29
1
2
3
4
5
6
78
9
10
11
CAUTION:

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.
EBU25650
Removing a wheel
1. Loosen the wheel nuts.
Front
Specified fuse:
5.0 A
1. Wheel nut
1
1