Page 58 of 90

Periodic maintenance an d a djustment
7-9
7
5. Install the drain bolt and its new
gasket, and then tighten the bolt
to the specified torque.
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 d iesel
specification of “CD” or oils of a
hi gher quality than specifie d. In
a ddition, do not use oils la beled
“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
CoolantThe 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.
EAUM1296
To check the coolant level1. Place the vehicle on a level sur- face and hold it in an upright posi-
tion.TIPThe 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]
1. Transmission oil filler cap
2. O-ring
3. Transmission oil drain bolt
4. GasketTi ghtenin g torque:
Transmission oil drain bolt: 10 N·m (1.0 kgf·m, 7.4 lb·ft)
12
4
3
Recommen ded transmission oil:
Motor oil SAE 10W-40 type SG or
higher
Oil chan ge quantity:
0.50 L (0.53 US qt, 0.44 Imp.qt)
UB4B83E0.book Page 9 Thursday, September 9, 2021 8:47 AM
Page 60 of 90

Periodic maintenance an d a djustment
7-11
7 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.
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.
9. Start the engine, and then check the vehicle for coolant leakage. If
coolant is leaking, have a Yamaha
dealer check the cooling system.
EAU48394
Cleanin g the air filter elementThe 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 element by removing the wing bolt and its
washer.
3. Remove the sponge material from the air filter element frame.
Tightenin g torque:
Coolant drain bolt: 10 N·m (1.0 kgf·m, 7.4 lb·ft)
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):0.50 L (0.53 US qt, 0.44 Imp.qt)
1. Wing bolt
2. Washer
3. Air filter element
1 1
3 32
UB4B83E0.book Page 11 Thursday, September 9, 2021 8:47 AM
Page 85 of 90

Specifications
9-1
9
Dimensions:Overall length:1820 mm (71.7 in) (YZ85, YZ85N)
1895 mm (74.6 in) (YZ85LW, YZ85LWN)
Overall width: 760 mm (29.9 in)
Overall height:
1135 mm (44.7 in) (YZ85, YZ85N)
1175 mm (46.3 in) (YZ85LW, YZ85LWN)
Seat height:
840 mm (33.1 in) (YZ85, YZ85N)
885 mm (34.8 in) (YZ85LW, YZ85LWN)
Wheelbase:
1255 mm (49.4 in) (YZ85, YZ85N)
1285 mm (50.6 in) (YZ85LW, YZ85LWN)
Ground clearance:
320 mm (12.60 in) (YZ85, YZ85N)
360 mm (14.17 in) (YZ85LW, YZ85LWN)Wei ght:Curb weight:
73 kg (161 lb) (YZ85, YZ85N)
75 kg (165 lb) (YZ85LW, YZ85LWN)
Maximum rider weight: 62.0 kg (137 lb)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-40 type SG or higher
Quantity:
0.50 L (0.53 US qt, 0.44 Imp.qt)Coolant quantity:Radiator (including all routes):0.50 L (0.53 US qt, 0.44 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, YZ85N)
70/100-19 42M (YZ85LW, YZ85LWN)
Manufacturer/model:
DUNLOP/MX3SFRear tire:Type: With tube
Size:
90/100-14 49M (YZ85, YZ85N)
90/100-16 52M (YZ85LW, YZ85LWN)
Manufacturer/model:
DUNLOP/MX3SFront brake:Type:
Hydraulic single disc brake
UB4B83E0.book Page 1 Thursday, September 9, 2021 8:47 AM