Page 47 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.
U1SN80E0.book Page 3 Thursday, June 9, 2011 11:24 AM
Page 53 of 88

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.
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. Gasket
Tightening 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)
2 1
2
3
U1SN80E0.book Page 9 Thursday, June 9, 2011 11:24 AM
Page 54 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 idle for 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.
EAUM1294
To check the coolant level1. 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
1. Radiator cap
1. Correct coolant level
U1SN80E0.book Page 10 Thursday, June 9, 2011 11:24 AM
Page 65 of 88

PERIODIC MAINTENANCE AND ADJUSTMENT
7-21
7
Use only the specified brake flu-
id; otherwise, the rubber seals
may deteriorate, causing leak-
age.
Refill with the same type of
brake fluid. Adding a brake fluid
other than DOT 4 may result in a
harmful chemical reaction.
Be careful that water does not
enter the brake fluid reservoir
when refilling. Water will signifi-
cantly lower the boiling point of
the fluid and may result in vapor
lock.
NOTICE
ECA17640
Brake fluid may damage painted sur-
faces or plastic parts. Always clean
up spilled fluid immediately.As the brake pads wear, it is normal for
the brake fluid level to gradually go
down. A low brake fluid level may indi-
cate worn brake pads and/or brake sys-
tem leakage; therefore, be sure to
check the brake pads for wear and the
brake system for leakage. If the brakefluid level goes down suddenly, have a
Yamaha dealer check the cause before
further riding.
EAU22731
Changing the brake fluid Have a Yamaha dealer change the
brake fluid at the intervals specified in
the TIP after the periodic maintenance
and lubrication chart. In addition, have
the oil seals of the master cylinders and
calipers as well as the brake hoses re-
placed at the intervals listed below or
whenever they are damaged or leak-
ing.
Oil seals: Replace every two
years.
Brake hoses: Replace every four
years.
U1SN80E0.book Page 21 Thursday, June 9, 2011 11:24 AM
Page 82 of 88

SPECIFICATIONS
9-1
9
Dimensions:Overall length:YZ85 1818 mm (71.6 in)
(AUT)(BEL)(CHE)(DEU)(DNK)(ESP)(FIN)
(FRA)(GBR)(GRC)(IRL)(ITA)(NLD)(NOR)
(POL)(PRT)(SVN)(SWE)
YZ85 1821 mm (71.7 in) (ZAF)
YZ85B 1818 mm (71.6 in)
YZ85LW 1903 mm (74.9 in)
YZ85LWB 1903 mm (74.9 in)
Overall width: 758 mm (29.8 in)
Overall height:
YZ85 1161 mm (45.7 in)
YZ85B 1161 mm (45.7 in)
YZ85LW 1205 mm (47.4 in)
YZ85LWB 1205 mm (47.4 in)
Seat height: YZ85 864 mm (34.0 in)
YZ85B 864 mm (34.0 in)
YZ85LW 904 mm (35.6 in)
YZ85LWB 904 mm (35.6 in)
Wheelbase: YZ85 1255 mm (49.4 in)
(AUT)(BEL)(CHE)(DEU)(DNK)(ESP)(FIN)
(FRA)(GBR)(GRC)(IRL)(ITA)(NLD)(NOR)
(POL)(PRT)(SVN)(SWE)
YZ85 1258 mm (49.5 in) (ZAF)
YZ85B 1255 mm (49.4 in)
YZ85LW 1286 mm (50.6 in)
YZ85LWB 1286 mm (50.6 in) Ground clearance:
YZ85 351 mm (13.82 in)
YZ85B 351 mm (13.82 in)
YZ85LW 393 mm (15.47 in)
YZ85LWB 393 mm (15.47 in)
Weight:Curb weight:
YZ85 71 kg (157 lb)
YZ85B 71 kg (157 lb)
YZ85LW 73 kg (161 lb)
YZ85LWB 73 kg (161 lb)Engine:Engine type:Liquid cooled 2-stroke
Cylinder arrangement:
Single cylinder
Displacement: 84 cm ³
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
U1SN80E0.book Page 1 Thursday, June 9, 2011 11:24 AM