Page 48 of 88
PERIODIC MAINTENANCE AND ADJUSTMENT
7-3
7
√
5 *Cylinder Check cylinder for score marks or wear.
Clean.
√
Replace. √
NO. ITEM ROUTINE
After
break-in Every
race Every
third race Every
fifth race As
required
6 *Clutch Check clutch housing, friction plates, clutch plates
and clutch springs for wear or damage.
Adjust. √
√
Replace. √
7 *Transmission Change the transmission oil.
√
Check transmission for damage. √
Replace bearings. √
8 *Shift forks, guide bars,
shift cam
Replace if necessary. Check all parts for wear and damage.
√
9 *Rotor nut
(flywheel
magneto) Tighten.
√√√
10 *Kickstarter system Check idle gear for damage.
√
Replace if necessary.
11 *Exhaust system Check exhaust pipe and muffler for carbon deposits.
√
√
Clean. √
√
√
√
√
12
*Crankshaft Check crankshaft for carbon deposits and damage.
Clean.
U1SN81E0.book Page 3 Tuesday, June 12, 2012 3:17 PM
Page 54 of 88

PERIODIC MAINTENANCE AND ADJUSTMENT
7-9
7To 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.
EAU41448
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 case to collect the used
oil.
4. Remove the oil filler cap, the trans- mission oil drain bolt and its gasket
to drain the oil from the transmis-
sion. 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, 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. GasketTightening torque:Transmission oil drain bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Recommended transmission oil: See page 9-1.
Oil change quantity: 0.50 L (0.53 US qt, 0.44 Imp.qt)
1
2
3
U1SN81E0.book Page 9 Tuesday, June 12, 2012 3:17 PM
Page 55 of 88

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 idlefor several minutes while checking
it for oil leakage. If oil is leaking, im-
mediately 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.
EAUM1295
To 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 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.
2. Remove the radiator cap andcheck the coolant level in the radi-
ator. WARNING! Never attempt
to remove the radiator cap when
the engine is hot.
[EWA10381]
TIPThe coolant should be at the bottom of
the radiator filler neck. The level will
change with variation of engine temper-
ature.1. Radiator cap
1. Correct coolant level
U1SN81E0.book Page 10 Tuesday, June 12, 2012 3:17 PM
Page 67 of 88

PERIODIC MAINTENANCE AND ADJUSTMENT
7-22
7
EAU51720
Changing the brake fluid 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.
EAU22760
Drive chain slack The drive chain slack should be
checked before each ride and adjusted
if necessary.
EAU41411
To check the drive chain slack1. Install the removable sidestand and place the motorcycle on it.TIPWhen checking and adjusting the drive
chain slack, there should be no weight
on the motorcycle.2. Shift the transmission into the neu-tral position.
3. Measure the drive chain slack as shown. 4. If the drive chain slack is incorrect,
adjust it as follows.
EAU41483
To adjust the drive chain slack
Consult a Yamaha dealer before ad-
justing the drive chain slack.1. Loosen the axle nut and the lock- nut on each side of the swingarm.
2. To tighten the drive chain, turn the drive chain slack adjusting bolt on
each side of the swingarm in direc-
tion (a). To loosen the drive chain,
turn the adjusting bolt on each side
of the swingarm in direction (b),
and then push the rear wheel for-
ward. NOTICE: Improper drive
chain slack will overload the en-
Drive chain slack: 35.0–45.0 mm (1.38–1.77 in)
1. Drive chain slack
U1SN81E0.book Page 22 Tuesday, June 12, 2012 3:17 PM
Page 83 of 88

SPECIFICATIONS
9-1
9
Dimensions:Overall length:YZ85 1818 mm (71.6 in)
YZ85D 1818 mm (71.6 in)
YZ85LW 1903 mm (74.9 in)
YZ85LWD 1903 mm (74.9 in)
Overall width:
758 mm (29.8 in)
Overall height: YZ85 1161 mm (45.7 in)
YZ85D 1161 mm (45.7 in)
YZ85LW 1205 mm (47.4 in)
YZ85LWD 1205 mm (47.4 in)
Seat height: YZ85 864 mm (34.0 in)
YZ85D 864 mm (34.0 in)
YZ85LW 904 mm (35.6 in)
YZ85LWD 904 mm (35.6 in)
Wheelbase:
YZ85 1255 mm (49.4 in)
YZ85D 1255 mm (49.4 in)
YZ85LW 1286 mm (50.6 in)
YZ85LWD 1286 mm (50.6 in)
Ground clearance: YZ85 351 mm (13.82 in)
YZ85D 351 mm (13.82 in)
YZ85LW 393 mm (15.47 in)
YZ85LWD 393 mm (15.47 in)Weight:Curb weight:
YZ85 71 kg (157 lb)
YZ85D 71 kg (157 lb)
YZ85LW 73 kg (161 lb)
YZ85LWD 73 kg (161 lb)
Engine:Engine type:Liquid cooled 2-stroke
Cylinder arrangement:
Single cylinder
Displacement: 84 cm³
Bore × stroke:
47.5 × 47.8 mm (1.87 × 1.88 in)
Compression ratio:
8.20 : 1
Starting system: Kickstarter
Lubrication system: PremixEngine oil:Type:YAMALUBE 2RTransmission oil:Type:
YAMALUBE 4 (10W-40) or SAE 10W-40
Oil change quantity: 0.50 L (0.53 US qt, 0.44 Imp.qt)Cooling system:Radiator capacity (including all routes):
0.54 L (0.57 US qt, 0.48 Imp.qt)Air filter:Air filter element:Wet elementFuel:Recommended fuel:Premium unleaded gasoline only
Fuel tank capacity: 5.0 L (1.32 US gal, 1.10 Imp.gal)
Carburetor:Type × quantity:
PWK28 x 1Spark plug(s):Manufacturer/model: NGK/BR10EG
Spark plug gap: 0.5–0.6 mm (0.020–0.024 in)Clutch:Clutch type:Wet, multiple-discTransmission:Primary reduction ratio:
3.611 (65/18)
Final drive: Chain
Secondary reduction ratio: YZ85 3.428 (48/14)
YZ85D 3.428 (48/14)
YZ85LW 3.714 (52/14)
YZ85LWD 3.714 (52/14)
Transmission type:
Constant mesh 6-speed
Operation: Left foot operation
Gear ratio: 1st:2.454 (27/11)
2nd: 1.882 (32/17)
3rd:
1.529 (26/17)
4th: 1.294 (22/17)
U1SN81E0.book Page 1 Tuesday, June 12, 2012 3:17 PM