2016 YAMAHA YZ85 engine

Periodic maintenance an d a djustment
7-7
7 To install the spark plu
g
1. Clean the surface of the spark plug gasket and its mating surfa-
ce, 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.
TIP
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
specified torque as soon as possible.
3. Install the spark plug cap.
EAU41449
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 lubrica-
tion 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
position.
3. Place an oil pan under the trans- mission case to collect the used
oil.
4. Remove the oil filler cap, the trans- mission oil drain bolt and its gas-
ket to drain the oil from the
transmission.
5. Install the drain bolt and its new gasket, and then tighten the bolt
to the specified torque.
Tightenin g 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)
1
2
3
U1SN84E0.book Page 7 Wednesday, June 10, 2015 10:24 AM

Periodic maintenance an d a djustment
7-8
7
6. Refill with the specified amount of
the recommended transmission
oil, and then install and tighten the
oil filler cap.
NOTICE
ECA10453
In or der to prevent clutch slip-
pa ge (since the transmission oil
also lu bricates the clutch), do
not mix any chemical additives.
Do not use oils with a diesel
specification of “CD” or oils of a
hi gher quality than specifie d. In
a ddition, do not use oils la bele d
“ENERGY CONSERVING II” or
hi gher.
 Make sure that no forei gn mate-
rial enters the transmission.
7. Start the engine, and then let it idle for several minutes while checking
it for oil leakage. If oil is leaking,
immediately turn the engine off
and check for the cause.
EAU20071
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.
EAUM1296To check the coolant level1. Place the vehicle on a level surfa- ce and hold it in an upright posi-
tion.
TIP
The coolant level must be
checked on a cold engine since
the level varies with engine tem-
perature.
 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.
2. Remove the radiator cap and
check the coolant level in the radi-
ator. WARNING! Never attempt
to remove the ra diator cap
when the en gine is hot.
[EWA10382]
Recommen ded transmission oil:
See page 9-1.
Oil chan ge quantity:
0.51 L (0.54 US qt, 0.45 Imp.qt)
1. Radiator cap
1
U1SN84E0.book Page 8 Wednesday, June 10, 2015 10:24 AM

Periodic maintenance an d a djustment
7-9
7
TIP
The coolant should be at the bottom of
the radiator filler neck. The level will
change with variation of engine tem-
perature.
3. If the coolant is below the correct
coolant level, add coolant, and
then install the radiator cap.
NOTICE: If coolant is not avail-
a b le, use distille d water or soft
tap water instea d. Do not use
har d water or salt water since it
is harmful to the en gine. If water
has been used instead of cool-
ant, replace it with coolant as
soon as possi ble, otherwise the
coolin g system will not be pro-
tected against frost an d corro-
sion. If water has b een added to
the coolant, have a Yamaha
d ealer check the antifreeze con-
tent of the coolant as soon as
possi ble, otherwise the effec-
tiveness of the coolant will be
re duce d.
[ECA10473]
EAUM1318
To change the coolant
1. Place the vehicle on a level surfa- ce and let the engine cool if neces-
sary. 2. Place a container under the en-
gine to collect the used coolant.
3. Remove the radiator cap, and then the coolant drain bolt and its
gasket to drain the cooling sys-
tem. WARNING! Never attempt
to remove the ra diator cap
when the en gine is hot.
[EWA10382]
4. After the coolant is completely
drained, thoroughly flush the cool-
ing system with clean tap water.
5. Install the coolant drain bolt and its new gasket, and then tighten
the bolt to the specified torque.
1. Correct coolant level
1
1. Radiator cap
1. Coolant drain bolt
2. Gasket
Tightening torque:
Coolant drain bolt: 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
1
12
U1SN84E0.book Page 9 Wednesday, June 10, 2015 10:24 AM

Periodic maintenance an d a djustment
7-10
7
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 minu-
tes, 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.
EAU48392
Cleanin g 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 4-8.)
2. Remove the air filter case cover as shown.
3. Remove the air filter element by removing the wing bolt and its
washer.
Antifreeze/water mixture ratio:1:1
Recommen ded antifreeze:
High-quality ethylene glycol anti-
freeze containing corrosion inhibi-
tors for aluminum engines
Coolant quantity:
Radiator (including all routes):0.54 L (0.57 US qt, 0.48 Imp.qt)
1. Air filter case cover
U1SN84E0.book Page 10 Wednesday, June 10, 2015 10:24 AM

Periodic maintenance an d a djustment
7-12
7
10. Install the air filter case cover in the original position as shown.
11. Install the seat.
EAU42111
A djustin g the car buretor
The carburetor is an important part of
the engine and requires very sophisti-
cated adjustment. Therefore, most
carburetor adjustments should be left
to a Yamaha dealer, who has the nec-
essary professional knowledge and ex-
perience. The adjustment described in
the following section, however, may be
serviced by the owner as part of rou-
tine maintenance.
NOTICE
ECA10551
The car buretor has b een set and ex-
tensively teste d at the Yamaha fac-
tory. Chan gin g these settin gs
without sufficient technical knowl-
e dge may result in poor perfor-
mance of or d amage to the en gine.
1. Air filter element
2. Projection
1. Washer
1
U1SN84E0.book Page 12 Wednesday, June 10, 2015 10:24 AM

Periodic maintenance an d a djustment
7-13
7
EAU44391
A djustin g the en gine i dlin g
spee d
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).
EAU48433
Adjustin g the throttle grip free
play
The throttle grip free play should mea-
sure 3.0–5.0 mm (0.12–0.20 in) at the
inner edge of the throttle grip. Periodi-
cally check the throttle grip free play
and, if necessary, adjust it as follows.
TIP
The engine idling speed must be cor-
rectly adjusted before checking and
adjusting the throttle grip free play.
1. Slide the rubber cover back.
2. Loosen the locknut.
3. To increase the throttle grip free
play, turn the adjusting nut in di-
rection (a). To decrease the throt-
tle grip free play, turn the adjusting
nut in direction (b).1. Throttle stop screw
1. Throttle grip free play
U1SN84E0.book Page 13 Wednesday, June 10, 2015 10:24 AM

Periodic maintenance an d a djustment
7-28
7
EAU24351
Supportin g the motorcycle
Since this model is not equipped with a
centerstand, follow these precautions
when removing the front and rear
wheel or performing other mainte-
nance requiring the motorcycle to
stand upright. Check that the motorcy-
cle is in a stable and level position be-
fore starting any maintenance. A
strong wooden box can be placed un-
der the engine for added stability.
To service the front wheel
1. Stabilize the rear of the motorcy- cle by using a motorcycle stand
or, if an additional motorcycle
stand is not available, by placing a
jack under the frame in front of the
rear wheel.
2. Raise the front wheel off the ground by using a motorcycle
stand.
To service the rear wheel
Raise the rear wheel off the ground by
using a motorcycle stand or, if a motor-
cycle stand is not available, by placing
a jack either under each side of the
frame in front of the rear wheel or under
each side of the swingarm.
EAU24361
Front wheel
EAU56371
To remove the front wheel
WARNING
EWA10822
To avoi d injury, securely support the
vehicle so there is no dan ger of it
fallin g over.
1. Loosen the axle nut.
2. Lift the front wheel off the ground
according to the procedure in the
previous section “Supporting the
motorcycle”.
3. Remove the axle nut and washer.
4. Pull the wheel axle out, and then remove the wheel. NOTICE: Do
not apply the b rake after the
wheel an d b rake disc have been
remove d, otherwise the brake
pa ds will be forced shut.
[ECA11073]
1. Washer
2. Axle nut
U1SN84E0.book Page 28 Wednesday, June 10, 2015 10:24 AM

Periodic maintenance an d a djustment
7-32
7
EAU66360
Trou bleshootin g charts
Startin g pro blems or poor en gine performance
1. FuelThere is enough fuel.
There is no fuel.
Check the ignition.
Supply fuel.The engine does not
start.
Check the ignition.
Open the throttle
halfway and operate
the kickstarter.Wipe off with a dry
cloth and correct the
spark plug gap, or
replace the spark
plug.
2. IgnitionWet
Dry
There is compression.
There is no
compression.
The engine does not start.
Have a Yamaha dealer check the vehicle.
Have a Yamaha dealer check the vehicle.
The engine does not
start.
Check the
compression.Have a Yamaha
dealer check the
vehicle.
Remove the spark
plug and check
the electrodes.
Operate the
kickstarter.
Check the fuel level
in the fuel tank.
3. Compression
U1SN84E0.book Page 32 Wednesday, June 10, 2015 10:24 AM