2008 YAMAHA YFM80R Owners Manual

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To change the final gear oil
1. Place the ATV on a level surface.
2. Place an oil pan under the final gear case to
collect the used oil.
3. Remove the final gear oil filler cap and the fi-
nal gear oil drain bolt to drain the oil from the
final gear case.
4. Install the drain bolt, and then tighten it to the
specified torque.5. Add the specified amount of the recommend-
ed final gear oil, and then check the oil level.
CAUTION:
ECB00420
Be sure no foreign material enters the final
gear case.
6. Install and tighten the oil filler cap.
7. Check the final gear case for oil leakage. If oil
is leaking, check for the cause.
EBU23802
Cleaning the air filter element
The air filter element should be cleaned at the in-
tervals specified in the periodic maintenance and
lubrication chart. Clean the air filter element more
frequently if you are riding in unusually wet or dusty
areas.
NOTE:

There is a check hose at the bottom of the air filter
case. If dust or water collects in this hose, empty
1. Final gear oil drain bolt
Tightening torque:
Final gear oil drain bolt:
23 Nm (2.3 m·kgf, 16.6 ft·lbf)
1

Recommended final gear oil:
See page 10-1.
Oil quantity:
0.12 L (0.13 US qt) (0.11 Imp.qt)

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the hose and clean the air filter element and air fil-
ter case.
1. Remove the panel shown by removing the
bolts.2. Remove the air filter case cover by unhooking
the holders.
1. Air filter case check hose
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1. Panel
2. Bolt
122

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3. Unhook the holder holding the air filter ele-
ment, and then pull out the sponge material
from the air filter element.4. Wash the sponge material gently but thor-
oughly in solvent.
WARNING

EWB01940
Always use parts cleaning solvent to clean the
sponge material. Never use low-flash-point
solvents or gasoline to clean the sponge mate-
rial because the engine could catch fire or ex-
plode.
5. Squeeze the excess solvent out of the sponge
material and let it dry.
1. Air filter case cover
2. Air filter case holder
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1. Air filter element holder
2. Sponge material
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CAUTION:

ECB00440
Do not twist the sponge material when squeez-
ing it.
6. Check the sponge material and replace it if
damaged.
7. Apply a quality foam air filter oil to the sponge
material.
NOTE:

The sponge material should be wet but not drip-
ping.
8. Install the sponge material into the air filter el-
ement.9. Place the air filter element in the original posi-
tion, and then hook the holder.
10. Install the air filter case cover by hooking the
holders onto the air filter case.
11. Install the panel by installing the bolts.
NOTE:

The air filter element should be cleaned every 20–
40 hours. It should be cleaned and lubricated more
often if the ATV is operated in extremely dusty ar-
eas. Each time the air filter element maintenance
is performed, check the air inlet of the air filter case
for obstructions.
CAUTION:

ECB00460

Make sure that the air filter element is prop-
erly seated in the air filter case.

Never operate the engine with the air filter el-
ement removed. This will allow unfiltered air
to enter the engine, causing rapid engine
wear and possible engine damage. Addition-
ally, operation without the air filter element
will affect carburetor jetting with subsequent
poor performance and possible engine over-
heating.

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EBU23850
Removing the air intake restrictor plate
To obtain full engine performance capability, re-
moving the air intake restrictor plate is required.
1. Remove the air filter element. (See
page 8-13.)
2. Remove the air intake restrictor plate.
NOTE:

Store the air intake restrictor plate with the owner’s
manual so that it is readily available whenever you
want to reduce the top speed.
3. Install the air filter element.
EBU27630
Cleaning the spark arrester
Be sure the exhaust pipe and muffler are cool be-
fore cleaning the spark arrester.
1. Remove the screws.
2. 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.
1. Air intake restrictor plate
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1. Screw
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4. Insert the tailpipe into the muffler and align the
screw holes.
5. Install the screws and tighten them.
WARNING

EWB02340
Do not start the engine when cleaning the
spark arrester, otherwise it could cause injury
to the eyes, burns, carbon monoxide poison-
ing, possibly leading to death, and start a fire.
Always let the exhaust system cool prior to
touching exhaust components.
EBU23940
Adjusting the carburetor
The carburetor should be checked and, if neces-
sary, adjusted at the intervals specified in the peri-
odic maintenance and lubrication chart. The
carburetor is an important part of the engine and
requires very sophisticated adjustment. Therefore,
most carburetor adjustments should be left to a
Yamaha dealer, who has the necessary profes-
sional knowledge and experience. The adjustment
described in the following section, however, may
be performed by the owner as part of routine main-
tenance.CAUTION:

ECB00480
The carburetor has been set and extensively
tested at the Yamaha factory. Changing these
settings without sufficient technical knowl-
edge may result in poor performance of or
damage to the engine.
EBU24000
Adjusting the engine idling speed
The engine idling speed must be checked and, if
necessary, adjusted as follows at the intervals
specified in the periodic maintenance and lubrica-
1. Tailpipe
2. Spark arrester
3. Screw
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tion chart.
NOTE:

A diagnostic tachometer is needed to make this
adjustment.
1. Start the engine and warm it up.
NOTE:

The engine is warm when it quickly responds to the
throttle.
2. Attach the tachometer to the spark plug lead.
3. Check the engine idling speed and, if neces-
sary, adjust it to specification by turning the
throttle stop screw at the carburetor. To in-
crease the engine idling speed, turn the throt-
tle stop screw in direction (a), and to decrease
it, turn the screw in direction (b).
NOTE:

If the specified idling speed cannot be obtained as
described above, have a Yamaha dealer make the
adjustment.
EBU27071
Checking the throttle cable free play
The throttle cable free play should be checked at
the intervals specified in the periodic maintenance
and lubrication chart.
1. Throttle stop screw
Engine idling speed:
1700–1900 r/min
1 (a) (b)

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The throttle cable free play should measure 1.0–
3.0 mm (0.04–0.12 in) at the throttle lever. Period-
ically check the throttle cable free play and, if nec-
essary, have a Yamaha dealer adjust it.
EBU24050
Timing chain
The timing chain stretches with use, resulting in im-
proper valve timing and engine noise. To prevent
this from occurring, the timing chain tensioner
must be adjusted by a Yamaha dealer at the inter-
vals specified in the periodic maintenance and lu-
brication chart.
EBU24060
Valve clearance
The valve clearance changes with use, resulting in
improper air-fuel mixture and/or engine noise. To
prevent this from occurring, the valve clearance
must be adjusted by a Yamaha dealer at the inter-
vals specified in the periodic maintenance and lu-
brication chart.
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.
1. Throttle lever free play
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