transmission YAMAHA YZ85 2021 User Guide

Periodic maintenance an d a djustment
7-3
7
10 *Rotor nut
(flywheel magneto) Tighten.
11 *
Kickstarter system Check idle gear for damage. Replace if necessary.
Check exhaust pipe and muffler for
carbon deposits.

12 *Exhaust system
Clean.
 Check crankshaft for carbon depositsand damage.13 *Crankshaft
Clean.
 


14 *
Carburetor Check carburetor settings and for
obstructions.
Adjust and clean. Check condition.
15Spark plug Clean and regap.
Replace.
 Check chain slack, alignment and
condition.
16 *Drive chain Adjust and thoroughly lubricate chain
with Yamaha chain and cable lube or
equivalent.
Replace.
NO. ITEM ROUTINE
After
break-in
Everyrace
Every
third race
Every
fifth race
As
required
7 *Clutch Check clutch housing, friction plates,
clutch plates and clutch springs for
wear or damage.
Adjust.
Replace.

8 *
Transmission Change the transmission oil. Check transmission for damage. Replace bearings.
9 *Shift forks, guide
bars, shift cam Check all parts for wear and damage. Replace if necessary.
UB4B82E0.book Page 3 Wednesday, March 11, 2020 1:10 PM

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 sur-
face, 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 asshown.
EAU4144C
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 transmission oil filler cap and its O-ring, and then re-
move the transmission oil drain
bolt and its gasket 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.
Tightening torque:
Spark plug: 20 N·m (2.0 kgf·m, 15 lb·ft)
1. Spark plug cap
1
1. Transmission oil filler cap
2. O-ring
3. Transmission oil drain bolt
4. Gasket
1
2
43
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Periodic maintenance an d a djustment
7-8
7 6. Refill with the specified amount of
the recommended transmission
oil.
NOTICE
ECA10453
In or der to prevent clutch slip-
pa ge (since the transmission oil
also lu bricates the clutch), d o
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. Check the O-ring for damage, and replace it if necessary.
8. Install and tighten the transmis- sion oil filler cap and its O-ring.
9. 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 sur- face 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]
Ti ghtenin g torque:
Transmission oil drain bolt: 10 N·m (1.0 kgf·m, 7.4 lb·ft)
Recommen ded transmission oil:
Motor oil SAE 10W-30 type SE or
higher or Gear oil SAE 85W GL-3
Oil chan ge quantity:
0.50 L (0.53 US qt, 0.44 Imp.qt)
1. Radiator cap
1
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Periodic maintenance an d a djustment
7-21
7
EAU51721
Chan gin g the brake flui d
Have a Yamaha dealer change the
brake fluid at the intervals specified in
the periodic maintenance and lubrica-
tion chart. In addition, have the oil seals
of the master cylinders and calipers as
well as the brake hoses replaced at the
intervals listed below or whenever they
are damaged or leaking.
 Oil seals: Replace every two
years.
 Brake hoses: Replace every four
years.
EAU22762
Drive chain slack
The drive chain slack should be
checked before each ride and adjusted
if necessary.
EAU84400To check the d rive chain slack
1. Place the motorcycle on a suitable stand. (See page 7-28.)
2. Confirm the rear wheel is off the ground and the rear shock ab-
sorber is fully extended.
3. Shift the transmission into neutral.
4. Pull up the drive chain until the chain is taut, and then measure
distance A between the top of the
swingarm and the bottom of the
chain as shown.
5. If the drive chain slack is incorrect, adjust it as follows. NOTICE: Im-
proper drive chain slack will
overload the engine as well as
other vital parts of the motorcy-
cle an d can lead to chain slip-
pa ge or breakag e. To prevent
1. Distance A
Distance A:
58.0–68.0 mm (2.28–2.68 in) (YZ85,
YZ85M)
65.0–75.0 mm (2.56–2.95 in)
(YZ85LW, YZ85LWM)
1
UB4B82E0.book Page 21 Wednesday, March 11, 2020 1:10 PM

Specifications
9-1
9
Dimensions:
Overall length:1820 mm (71.7 in) (YZ85, YZ85M)
1895 mm (74.6 in) (YZ85LW, YZ85LWM)
Overall width: 760 mm (29.9 in)
Overall height:
1145 mm (45.1 in) (YZ85, YZ85M)
1175 mm (46.3 in) (YZ85LW, YZ85LWM)
Seat height:
840 mm (33.1 in) (YZ85, YZ85M)
870 mm (34.3 in) (YZ85LW, YZ85LWM)
Wheelbase:
1255 mm (49.4 in) (YZ85, YZ85M)
1285 mm (50.6 in) (YZ85LW, YZ85LWM)
Ground clearance: 330 mm (12.99 in) (YZ85, YZ85M)
360 mm (14.17 in) (YZ85LW, YZ85LWM)
Wei ght:
Curb weight:
73 kg (161 lb) (YZ85, YZ85M)
75 kg (165 lb) (YZ85LW, YZ85LWM)
Engine:
Combustion cycle:
2-stroke
Cooling system: Liquid cooled
Number of cylinders:
Single cylinder
Displacement: 85 cm³
Bore × stroke:
47.5 × 47.8 mm (1.87 × 1.88 in)
Starting system:
Kickstarter
Engine oil:
Engine oil:
YAMALUBE 2R
Recommended brand:
Transmission oil:
Type:
Motor oil SAE 10W-30 type SE or higher or
Gear oil SAE 85W GL-3
Quantity:
0.50 L (0.53 US qt, 0.44 Imp.qt)
Coolant quantity:
Radiator (including all routes): 0.55 L (0.58 US qt, 0.48 Imp.qt)
Fuel:
Recommended fuel:Unleaded gasoline (E10 acceptable)
Octane number (RON): 98
Fuel tank capacity:
5.0 L (1.3 US gal, 1.1 Imp.gal)
Car buretor:
Type × quantity:
PWK28 × 1
Drivetrain:
Gear ratio:
1st:
2.455 (27/11)
2nd:
1.882 (32/17)
3rd: 1.529 (26/17)
4th: 1.294 (22/17)
5th:
1.130 (26/23)
6th: 1.000 (25/25)
Front tire:
Type:
With tube
Size: 70/100-17 40M (YZ85, YZ85M)
70/100-19 42M (YZ85LW, YZ85LWM)
Manufacturer/model: DUNLOP/MX3SF
Rear tire:
Type:
With tube
Size: 90/100-14 49M (YZ85, YZ85M)
90/100-16 52M (YZ85LW, YZ85LWM)
Manufacturer/model: DUNLOP/MX3S
Front brake:
Type:
Hydraulic single disc brake
Rear brake:
Type:
Hydraulic single disc brake
UB4B82E0.book Page 1 Wednesday, March 11, 2020 1:10 PM

11-1
11
Index
A
Air filter element, cleaning .................... 7-10
B
Brake and clutch levers, checking and
lubricating .......................................... 7-24
Brake fluid, changing ........................... 7-21
Brake fluid level, checking ................... 7-20
Brake lever ............................................. 4-2
Brake lever free play, checking ............ 7-18
Brake pedal ............................................ 4-3
Brake pedal, checking and lubricating .......................................... 7-25
C
Cables, checking and lubricating ......... 7-23
Carburetor, adjusting ........................... 7-12
Care ........................................................ 8-1
Clutch lever ............................................ 4-1
Clutch lever free play, adjusting ........... 7-17
Coolant ................................................... 7-8
D
Drive chain, cleaning and lubricating ... 7-23
Drive chain slack .................................. 7-21
E
Engine break-in ...................................... 6-1
Engine idling speed .............................. 7-13
Engine overheating............................... 7-33
Engine serial number............................ 10-1
Engine, starting a warm ......................... 6-3
Engine stop switch ................................. 4-1
F
Front and rear brake pads, checking ... 7-19
Front fork, adjusting ............................... 4-9
Front fork, bleeding .............................. 4-11
Front fork, checking ............................. 7-26
Fuel......................................................... 4-4
Fuel cock ................................................ 4-7
Fuel tank breather hose ......................... 4-6
Fuel tank cap.......................................... 4-3
H
Handlebar switch ................................... 4-1
I
Identification numbers.......................... 10-1
K
Kickstarter .............................................. 4-8
L
Labels, location ...................................... 1-1
M
Matte color, caution ............................... 8-1
P
Parking ................................................... 6-5 Part locations .......................................... 3-1
Periodic maintenance and lubrication
chart ..................................................... 7-2
R
Rear suspension, lubricating ................ 7-25
S
Safety defects, reporting (For CANADA customers) .......................................... 10-2
Safety information................................... 2-1
Seat......................................................... 4-8
Shifting .................................................... 6-4
Shift pedal............................................... 4-2
Shift pedal, checking ............................ 7-18
Shock absorber assembly, adjusting ... 4-12
Sidestand .............................................. 4-15
Spark plug, checking .............................. 7-6
Specifications ......................................... 9-1
Starter (choke) knob ............................... 4-7
Starting and warming up a cold engine ................................................... 6-3
Steering, checking ................................ 7-27
Storage ................................................... 8-4
Supporting the motorcycle ................... 7-28
Swingarm pivots, lubricating ................ 7-26
T
Throttle grip and cable, checking and lubricating ........................................... 7-24
Throttle grip free play, adjusting ........... 7-13
Tires ...................................................... 7-14
Transmission oil ...................................... 7-7
Troubleshooting .................................... 7-31
Troubleshooting chart........................... 7-32
V
Vehicle identification number ............... 10-1
W
Wheel bearings, checking..................... 7-27
Wheel (front).......................................... 7-28
Wheel (rear) ........................................... 7-29
Wheels .................................................. 7-16
Y
YPVS system ........................................ 4-16
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