YAMAHA YZ85 2010 Workshop Manual

PERIODIC MAINTENANCE AND ADJUSTMENT
7-7
7 Every two years replace the internal components of the brake master cylinders and calipers, and change the brake
fluid.
Replace the brake hoses every four years and if cracked or damaged.
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PERIODIC MAINTENANCE AND ADJUSTMENT
7-8
7
EAU19613
Checking the spark plug The spark plug is an important engine
component, which is easy to check.
Since heat and deposits will cause any
spark plug to slowly erode, the spark
plug should be removed and checked
in accordance with the periodic mainte-
nance and lubrication chart. In addition,
the condition of the spark plug can re-
veal the condition of the engine.
To remove the spark plug
1. Remove the spark plug cap.
2. Remove the spark plug as shown,
with a spark plug wrench available
at a Yamaha dealer.To check the spark plug
1. Check that the porcelain insulator
around the center electrode of the
spark plug is a medium-to-light tan
(the ideal color when the vehicle is
ridden normally).
TIPIf the spark plug shows a distinctly dif-
ferent color, the engine could be oper-
ating improperly. Do not attempt to
diagnose such problems yourself. In-
stead, have a Yamaha dealer check
the vehicle.
2. Check the spark plug for electrode
erosion and excessive carbon or
other deposits, and replace it if
necessary.
3. Measure the spark plug gap with a
wire thickness gauge and, if nec-
essary, adjust the gap to specifica-
tion.
1. Spark plug cap
1. Spark plug wrench
Specified spark plug:
NGK/BR10EG1. Spark plug gapSpark plug gap:
0.5–0.6 mm (0.020–0.024 in)
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PERIODIC MAINTENANCE AND ADJUSTMENT
7-9
7 To install the spark plug
1. Clean the surface of the spark plug
gasket and its mating surface, and
then wipe off any grime from the
spark plug threads.
2. Install the spark plug with the
spark plug wrench, and then tight-
en it to the specified torque.
TIPIf 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.3. Install the spark plug cap.
EAU41445
Transmission oil The transmission 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, the drain
bolt and the gasket to drain the oil
from the transmission.5. Install a new gasket and the trans-
mission oil drain bolt, and then
tighten the bolt to the specified
torque.
6. Refill with 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. Transmission oil filler cap
2. Transmission oil drain bolt
3. Gasket
Tightening torque:
Transmission oil drain bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
21
2
3
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PERIODIC MAINTENANCE AND ADJUSTMENT
7-10
7
NOTICE
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.
EAUM1294
To check the coolant level
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion.
2. Remove the radiator cap and
check the coolant level in the radi-
ator. WARNING! Never attempt
to remove the radiator cap when
the engine is hot.
[EWA10381]
TIP

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 the
side can result in a false reading.
TIPThe coolant should be at the bottom of
the radiator filler neck. The level will
change with variation of engine temper-
ature.3. If the coolant is below this level,
add coolant, and then install the
radiator cap. NOTICE: If coolant
Recommended transmission oil:
See page 9-1.
Oil change quantity:
0.50 L (0.53 US qt, 0.44 Imp.qt)
1. Radiator cap
1. Correct coolant level
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PERIODIC MAINTENANCE AND ADJUSTMENT
7-11
7 is not available, use distilled wa-
ter 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 anti-
freeze content of the coolant as
soon as possible, otherwise the
effectiveness of the coolant will
be reduced.
[ECA10472]
EAUM1314
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.
3. Remove the coolant drain bolt and
the gasket, and then the radiator
cap to drain the cooling system.WARNING! Never attempt to re-
move the radiator cap when the
engine is hot.
[EWA10381]
4. After the coolant is completely
drained, thoroughly flush the cool-
ing system with clean tap water.5. Install a new gasket and the cool-
ant drain bolt, and then tighten the
bolt to the specified torque.
6. Pour the recommended coolant
into the radiator until it is full.
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.1. Coolant drain bolt
2. Gasket
1. Radiator cap
1
1
2
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 ADJUSTMENT
7-12
79. Start the engine, and then check
the vehicle for coolant leakage. If
coolant is leaking, have a Yamaha
dealer check the cooling system.
EAU41433
Cleaning the air filter element The air filter element should be cleaned
or replaced at the intervals specified in
the periodic maintenance and lubrica-
tion chart. Clean or, if necessary, re-
place the air filter element more
frequently if you are riding in unusually
wet or dusty areas.
1. Remove the seat. (See page 4-7.)
2. Remove the air filter case cover as
shown.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.1. Air filter case cover
1. Wing bolt
2. Washer
3. Air filter element
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PERIODIC MAINTENANCE AND ADJUSTMENT
7-13
7 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.
TIPThe sponge material should be wet but
not 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. NOTICE:
Make sure that the air filter ele-
ment is properly seated in the
air filter case. The engine
should never be operated with-
out the air filter element in-
stalled, otherwise the piston(s)
and/or cylinder(s) may become
excessively worn.
[ECA10481]
9. Install the air filter case cover in the
original position as shown.
10. Install the seat.
1. Sponge material
2. Air filter element frame
Recommended oil:
Yamaha foam air filter oil or other
quality foam air filter oil
1. Air filter element
2. Projection
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PERIODIC MAINTENANCE AND ADJUSTMENT
7-14
7
EAU42110
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.NOTICE
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).
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.TIPThe engine idling speed must be cor-
rectly adjusted before checking and ad-
justing the throttle cable free play.1. Loosen the locknut.
1. Throttle stop screw
1. Throttle cable free play
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PERIODIC MAINTENANCE AND ADJUSTMENT
7-15
7 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.
EAU41821
Tires To maximize the performance, durabil-
ity, and safe operation of your motorcy-
cle, 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
EWA14381
Operation of this vehicle with im-
proper tire pressure may cause se-
vere injury or death from loss of
control.

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.
Tire inspection
The tires must be checked before each
ride.NOTICE
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.
1. Locknut
2. Throttle cable free play adjusting nut
Standard tire air pressure:
Front:
100 kPa (1.00 kgf/cm², 15 psi)
Rear:
100 kPa (1.00 kgf/cm², 15 psi)
1. Tire sidewall
2. Tire tread depth
12
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PERIODIC MAINTENANCE AND ADJUSTMENT
7-16
7


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
EWA10461
The front and rear tires should be of
the same make and design, other-
wise the handling characteristics of
the vehicle may be different, which
could lead to an accident.
After extensive tests, only the tires list-
ed below have been approved for this
model by Yamaha 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.


The replacement of all wheel-
and brake-related parts, includ-
ing the tires, should be left to a
Yamaha dealer, who has the
necessary professional knowl-
edge and experience.


It is not recommended to patch
a punctured tube. If unavoid-
able, however, patch the tube
very carefully and replace it as
soon as possible with a high-
quality product.
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
YZ85LWZ 70/100-19 42M
YZ85Z 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)(IT
A)(NLD)(NOR)(POL)(PRT)(SVN)(
SWE)
YZ85LW DUNLOP/D739FA (ZAF)
YZ85LW DUNLOP/D756F
(AUT)(BEL)(CHE)(DEU)(DNK)(ES
P)(FIN)(FRA)(GBR)(GRC)(IRL)(IT
A)(NLD)(NOR)(POL)(PRT)(SVN)(
SWE)
YZ85LWZ DUNLOP/D756F
YZ85Z DUNLOP/D756F
Rear tire:
Size:
YZ85 90/100-14 49M
YZ85LW 90/100-16 52M
YZ85LWZ 90/100-16 52M
YZ85Z 90/100-14 49M
Manufacturer/model:
DUNLOP/D756
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