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PERIODIC MAINTENANCE AND MINOR REPAIR
6-9
6 2. Clean the surface of the spark plug
gasket and its mating surface, and
then wipe off any grime from the
spark plug threads.
3. Install the spark plug with the
spark plug wrench, and then tight-
en it to the specified torque.
NOTE:
If a torque wrench is not available when
installing a spark plug, a good estimate
of the correct torque is 1/4–1/2 turn
past finger tight. However, the spark
plug should be tightened to the speci-fied torque as soon as possible.
4. Install the spark plug cap.
EAU41441
Transmission oil The transmission oil must be checked
for oil leakage before each ride. If any
leakage is found, have a Yamaha deal-
er check and repair the motorcycle. In
addition, the transmission oil must be
changed at the intervals specified in the
periodic maintenance and lubrication
chart.
1. Start the engine, warm it up for
several minutes, and then turn it
off.
2. Place the motorcycle on a level
surface and hold it in an upright po-
sition.
3. Place an oil pan under the trans-
mission to collect the used oil.
4. Remove the oil filler cap and drain
bolt to drain the oil from the trans-
mission.5. Install the transmission oil drain
bolt, and then tighten it to the spec-
ified torque.
6. Add the specified amount of the
recommended transmission oil,
and then install and tighten the oil
filler cap.
Tightening torque:
Spark plug:
20 Nm (2.0 m·kgf, 14 ft·lbf)
1. Oil filler cap
2. Transmission oil drain bolt
Tightening torque:
Transmission oil drain bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Recommended transmission oil:
See page 8-1.
Oil change quantity:
0.50 L (0.53 US qt) (0.44 Imp.qt)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-10
6
CAUTION:
ECA10452
In order to prevent clutch slip-
page (since the transmission oil
also lubricates the clutch), do
not mix any chemical additives.
Do not use oils with a diesel
specification of “CD” or oils of a
higher quality than specified. In
addition, do not use oils labeled
“ENERGY CONSERVING II” or
higher.
Make sure that no foreign mate-rial enters the transmission.
7. Start the engine, and then let it idle
for several minutes while checking
the transmission for oil leakage. If
oil is leaking, immediately turn the
engine off and check for the cause.
EAU20070
Coolant The coolant level should be checked
before each ride. In addition, the cool-
ant must be changed at the intervals
specified in the periodic maintenance
and lubrication chart.
EAUM1292
To check the coolant level
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion.
WARNING
EWA10380
Never attempt to remove the radiatorcap when the engine is hot.
2. Remove the radiator cap and
check the coolant level in the radi-
ator.
NOTE:
The coolant level must be checked
on a cold engine since the level
varies with engine temperature.
Make sure that the vehicle is posi-
tioned straight up when checking
the coolant level. A slight tilt to theside can result in a false reading.
NOTE:The coolant should be at the bottom of
the radiator filler neck. The level will
change with variation of engine temper-ature.1. Radiator cap
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-11
6 3. If the coolant is below this level,
add coolant, and then install the
radiator cap.
NOTE:
If the engine overheats, see page 6-31for further instructions.
EAUM1312
To change the coolant
1. Place the vehicle on a level sur-
face and let the engine cool if nec-
essary.
2. Place a container under the engine
to collect the used coolant.
WARNING
EWA10380
Never attempt to remove the radiatorcap when the engine is hot.
3. Remove the coolant drain bolt and
then the radiator cap to drain the
cooling system.4. After the coolant is completely
drained, thoroughly flush the cool-
ing system with clean tap water.
5. Install the coolant drain bolt, and
then tighten it to the specified
torque.
NOTE:Check the washer for damage and re-place it if necessary.
6. Pour the recommended coolant
into the radiator until it is full.
1. Correct coolant level
1. Coolant drain bolt
1. Radiator cap
Tightening torque:
Coolant drain bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Antifreeze/water mixture ratio:
1:1
Recommended antifreeze:
High-quality ethylene glycol anti-
freeze containing corrosion inhibitors
for aluminum engines
Coolant quantity:
Radiator capacity (including all
routes):
0.54 L (0.57 US qt) (0.48 Imp.qt)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-12
6
CAUTION:
ECA10471
If coolant is not available, use
distilled water or soft tap water
instead. Do not use hard water
or salt water since it is harmful
to the engine.
If water has been used instead
of coolant, replace it with cool-
ant as soon as possible, other-
wise the cooling system will not
be protected against frost and
corrosion.
If water has been added to the
coolant, have a Yamaha dealer
check the antifreeze content of
the coolant as soon as possible,
otherwise the effectiveness ofthe coolant will be reduced.
7. Install the radiator cap, start the
engine, let it idle for several min-
utes, and then turn it off.
8. Remove the radiator cap to check
the coolant level in the radiator. If
necessary, add sufficient coolant
until it reaches the bottom of the
radiator filler neck, and then install
the radiator cap.9. Start the engine, and then check
the vehicle for coolant leakage. If
coolant is leaking, have a Yamaha
dealer check the cooling system.
EAU41431
Cleaning the air filter element The air filter element should be cleaned
at the intervals specified in the periodic
maintenance and lubrication chart.
Clean the air filter element more fre-
quently if you are riding in unusually
wet or dusty areas.
1. Remove the seat. (See page 3-6.)
2. Remove the air filter case cover as
shown.1. Air filter case cover
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-13
6 3. Remove the air filter element by
removing the wing bolt and wash-
er.
4. Remove the sponge material from
the air filter element frame.5. Clean the sponge material with
solvent, and then squeeze the re-
maining solvent out.
6. Apply oil of the recommended type
to the entire surface of the sponge
material, and then squeeze the ex-
cess oil out.
NOTE:The sponge material should be wet butnot dripping.
7. Pull the sponge material over the
air filter element frame.
8. Insert the air filter element into the
air filter case with the projection
facing upward, and then install the
washer and wing bolt.
1. Wing bolt
2. Washer
3. Sponge material
1. Sponge material
2. Air filter element frame
Recommended oil:
Yamaha foam air filter oil or other
quality foam air filter oil
1. Sponge material
2. Projection
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-14
6
CAUTION:
ECA10480
Make sure that the air filter ele-
ment is properly seated in the
air filter case.
The engine should never be op-
erated without the air filter ele-
ment installed, otherwise the
piston(s) and/or cylinder(s) maybecome excessively worn.
9. Install the air filter case cover in the
original position as shown.
10. Install the seat.
EAU39930
Adjusting the carburetor The carburetor is an important part of
the engine and requires very sophisti-
cated adjustment. Therefore, most car-
buretor adjustments should be left to a
Yamaha dealer, who has the neces-
sary professional knowledge and expe-
rience. The adjustment described in the
following section, however, may be ser-
viced by the owner as part of routine
maintenance.CAUTION:
ECA10550
The carburetor has been set and ex-
tensively tested at the Yamaha fac-
tory. Changing these settings
without sufficient technical knowl-
edge may result in poor perfor-mance of or damage to the engine.
EAU44390
Adjusting the engine idling
speed The engine idling speed must be ad-
justed when necessary.
1. Start the engine and thoroughly
warm it up.
2. Turn the throttle stop screw until
the engine runs at the lowest pos-
sible speed.
3. To increase the engine idling
speed, turn the throttle stop screw
in direction (a). To decrease the
engine idling speed, turn the throt-
tle stop screw in direction (b).1. Throttle stop screw
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-15
6
EAU21370
Adjusting the throttle cable
free play The throttle cable free play should mea-
sure 3.0–5.0 mm (0.12–0.20 in) at the
throttle grip. Periodically check the
throttle cable free play and, if neces-
sary, adjust it as follows.NOTE:The engine idling speed must be cor-
rectly adjusted before checking and ad-justing the throttle cable free play.
1. Loosen the locknut.2. To increase the throttle cable free
play, turn the adjusting nut in direc-
tion (a). To decrease the throttle
cable free play, turn the adjusting
nut in direction (b).
3. Tighten the locknut.
EAU41820
Tires To maximize the performance, durabil-
ity, and safe operation of your motor-
cycle, note the following points
regarding the specified tires.
Tire air pressure
The tire air pressure should be checked
and, if necessary, adjusted before each
ride.
WARNING
EWA14380
The tire air pressure must be
checked and adjusted on cold
tires (i.e., when the temperature
of the tires equals the ambient
temperature).
The tire air pressure must be ad-
justed in accordance with the
weight of the rider, the riding
speed, and the riding condi-tions.
1. Throttle cable free play
1. Locknut
2. Throttle cable free play adjusting nut
Standard tire air pressure:
Front:
100 kPa (15 psi) (1.00 kgf/cm²)
Rear:
100 kPa (15 psi) (1.00 kgf/cm²)
U5PA86E0.book Page 15 Monday, April 9, 2007 3:16 PM
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-16
6Tire inspection
The tires must be checked before each
ride.
CAUTION:
ECA15580
Be sure the bead stoppers are
tightened. Loose bead stoppers
will cause the tire to slip off the
rim if tire pressure is too low.
Be sure the valve stem is posi-
tioned straight. A tilted valve
stem indicates that the tire has
slipped from its original posi-
tion on the rim. Rotate the tire
so that the valve stem is posi-tioned straight.If the center tread depth reaches the
specified limit, if the tire has a nail or
glass fragments in it, or if the sidewall is
cracked, have a Yamaha dealer re-
place the tire immediately.
Tire information
This motorcycle is equipped with spoke
wheels and tube tires.
WARNING
EWA10460
The front and rear tires should
be of the same make and de-
sign, otherwise the handling
characteristics of the vehicle
cannot be guaranteed.
After extensive tests, only the
tires listed below have been ap-
proved for this model byYamaha Motor Co., Ltd.
WARNING
EWA14390
Have a Yamaha dealer replace
excessively worn tires. Operat-
ing the motorcycle with exces-
sively worn tires decreases
riding stability and can lead to
loss of control.
1. Tire sidewall
2. Tire tread depth
12
Minimum tire tread depth (front and
rear):
4.0 mm (0.16 in)
Front tire:
Size:
YZ85 70/100-17 40M
YZ85LW 70/100-19 42M
YZ85LWX 70/100-19 42M
YZ85X 70/100-17 40M
Manufacturer/model:
YZ85 DUNLOP/D739FA (ZAF)
YZ85 DUNLOP/D756F
(AUT)(BEL)(CHE)(DEU)(DNK)(ES
P)(FIN)(FRA)(GBR)(GRC)(IRL)(N
LD)(NOR)(PRT)(SWE)
YZ85LW DUNLOP/D756F
YZ85LWX DUNLOP/D756F
YZ85X DUNLOP/D756F
Rear tire:
Size:
YZ85 90/100-14 49M
YZ85LW 90/100-16 52M
YZ85LWX 90/100-16 52M
YZ85X 90/100-14 49M
Manufacturer/model:
DUNLOP/D756
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