OPERATION AND IMPORTANT RIDING POINTS
5-3
5
EAU41502
Engine break-in 1. Before starting the engine, fill the
fuel tank with a break-in oil-fuel
mixture as follows.
2. Start and warm up the engine.
Check the operation of the controls
and the engine stop button. (See
page 3-1.)
3. Operate the motorcycle in the low-
er gears at moderate throttle open-
ings for five to eight minutes. Stop
the engine and check the spark
plug condition (see page 6-8); it
will show a rich condition during
break-in.
4. Allow the engine to cool. Restart
the engine and operate the motor-
cycle as in the step above for five
minutes. Then, very briefly shift to
the higher gears and check the
full-throttle response. Stop the en-
gine and check the spark plug.5. After again allowing the engine to
cool, restart and run the motor-
cycle for five more minutes. Full
throttle and the higher gears may
be used, but sustained full-throttle
operation should be avoided. Stop
the engine and check the spark
plug again.
6. Allow the engine to cool, remove
the cylinder head and cylinder, and
inspect the piston and cylinder.
Remove any high spots on the pis-
ton with #600-grit wet sandpaper.
Clean all components and careful-
ly reassemble the cylinder head
and cylinder.
WARNING
EWA10320
If you are not familiar with mainte-
nance work, have a Yamaha dealerdo it for you.
7. Drain the break-in oil-fuel mixture
from the fuel tank and refill with the
specified mix. (See page 3-3.)
8. Start the engine and check the op-
eration of the motorcycle through-
out its entire operating range. Stop
the engine and check the sparkplug condition. Restart the motor-
cycle and ride it for about 10 to 15
more minutes. The motorcycle will
now be ready to ride normally.
After the engine break-in period, thor-
oughly check the motorcycle for loose
parts, oil leakage and any other prob-
lems. Be sure to inspect and make ad-
justments thoroughly, especially cable
and drive chain slack and loose
spokes. In addition, check all fittings
and fasteners for looseness, and tight-
en if necessary.
CAUTION:
ECA15560
When any of the following parts
have been replaced, they must
be broken in.
Cylinder or crankshaft:
About one hour of break-in op-
eration is necessary.
Piston, rings or transmission
gears:
These parts require about 30
minutes of break-in operation at
half-throttle or less. Observe the
condition of the engine carefully
during operation.
Recommended 2-stroke engine oil:
See page 8-1.
Mixing ratio (gasoline to oil):
15:1
U5PA85E0.book Page 3 Thursday, April 13, 2006 3:06 PM
PERIODIC MAINTENANCE AND MINOR REPAIR
6-3
6
√
5
*CylinderCheck cylinder for score marks or wear.
Clean.√
Replace.√ NO. ITEM ROUTINEAfter
break-inEvery
raceEvery
third raceEvery
fifth raceAs
required
6*ClutchCheck clutch housing, friction plates, clutch plates
and clutch springs for wear or damage.
Adjust.√ √
Replace.√
7*TransmissionChange 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 systemCheck idle gear for damage.
√
Replace if necessary.
11*Exhaust system Check exhaust pipe and muffler for carbon deposits.√ √
Clean.√
√
√ √
√ 12*CrankshaftCheck crankshaft for carbon deposits and damage.
Clean.
U5PA85E0.book Page 3 Thursday, April 13, 2006 3:06 PM
PERIODIC MAINTENANCE AND MINOR REPAIR
6-9
6 2. Clean the surface of the spark plug
gasket and its mating surface, and
then wipe off any grime from the
spark plug threads.
3. Install the spark plug with the
spark plug wrench, and then tight-
en it to the specified torque.
NOTE:
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 speci-fied torque as soon as possible.
4. Install the spark plug cap.
EAU41441
Transmission oil The transmission oil 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 to collect the used oil.
4. Remove the oil filler cap and drain
bolt to drain the oil from the trans-
mission.5. Install the transmission oil drain
bolt, and then tighten it to the spec-
ified torque.
6. Add 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. Oil filler cap
2. Transmission oil drain bolt
Tightening torque:
Transmission oil drain bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Recommended transmission oil:
See page 8-1.
Oil change quantity:
0.50 L (0.53 US qt) (0.44 Imp.qt)
chapter6 Page 9 Tuesday, April 18, 2006 10:03 AM
PERIODIC MAINTENANCE AND MINOR REPAIR
6-10
6
CAUTION:
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
the transmission for oil leakage. If
oil is leaking, immediately 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.
EAUM1291
To check the coolant level
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion.
WARNING
EWA10380
Never attempt to remove the radiatorcap when the engine is hot.
2. Remove the radiator cap and
check the coolant level in the radi-
ator.
NOTE:
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 theside can result in a false reading.
NOTE:The coolant should be at the brim of the
radiator filler. The level will change withvariation of engine temperature.1. Radiator cap
chapter6 Page 10 Tuesday, April 18, 2006 10:03 AM
PERIODIC MAINTENANCE AND MINOR REPAIR
6-20
6
EAU22730
Changing the brake fluid Have a Yamaha dealer change the
brake fluid at the intervals specified in
the NOTE after the periodic mainte-
nance and lubrication chart. In addition,
have the oil seals of the master cylin-
ders 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.
EAU41410
To check the drive chain slack
1. Install the removable sidestand
and place the motorcycle on it.NOTE:When checking and adjusting the drive
chain slack, there should be no weighton the motorcycle.
2. Shift the transmission into the neu-
tral position.
3. Move the rear wheel by pushing
the motorcycle to locate the tight-
est portion of the drive chain, and
then measure the drive chain slack
as shown.4. If the drive chain slack is incorrect,
adjust it as follows.
EAU41480
To adjust 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
adjusting bolt on each side of the
swingarm in direction (a). To loos-
en the drive chain, turn the adjust-
ing bolt on each side of the
swingarm in direction (b), and then
push the rear wheel forward.
Drive chain slack:
35.0–45.0 mm (1.38–1.77 in)
1. Drive chain slack
U5PA85E0.book Page 20 Thursday, April 13, 2006 3:06 PM
SPECIFICATIONS
8-1
8
Dimensions:Overall length:
YZ85 1818 mm (71.6 in)
(AUT)(BEL)(CHE)(DEU)(DNK)(ESP)(FIN)(
FRA)(GBR)(GRC)(IRL)(NLD)(NOR)(PRT)(
SWE)
YZ85 1821 mm (71.7 in) (ZAF)
YZ85LW 1903 mm (74.9 in)
YZ85LWW 1903 mm (74.9 in)
YZ85W 1818 mm (71.6 in)
YZ85W1 1818 mm (71.6 in)
Overall width:
758 mm (29.8 in)
Overall height:
YZ85 1161 mm (45.7 in)
YZ85LW 1205 mm (47.4 in)
YZ85LWW 1205 mm (47.4 in)
YZ85W 1161 mm (45.7 in)
YZ85W1 1161 mm (45.7 in)
Seat height:
YZ85 864 mm (34.0 in)
YZ85LW 904 mm (35.6 in)
YZ85LWW 904 mm (35.6 in)
YZ85W 864 mm (34.0 in)
YZ85W1 864 mm (34.0 in)
Wheelbase:
YZ85 1255 mm (49.4 in)
(AUT)(BEL)(CHE)(DEU)(DNK)(ESP)(FIN)(
FRA)(GBR)(GRC)(IRL)(NLD)(NOR)(PRT)(
SWE)
YZ85 1258 mm (49.5 in) (ZAF)
YZ85LW 1286 mm (50.6 in)YZ85LWW 1286 mm (50.6 in)
YZ85W 1255 mm (49.4 in)
YZ85W1 1255 mm (49.4 in)
Ground clearance:
YZ85 351 mm (13.82 in)
YZ85LW 393 mm (15.47 in)
YZ85LWW 393 mm (15.47 in)
YZ85W 351 mm (13.82 in)
YZ85W1 351 mm (13.82 in)
Weight:With oil and fuel:
YZ85 71.0 kg (157 lb)
YZ85LW 73.9 kg (163 lb)
YZ85LWW 73.9 kg (163 lb)
YZ85W 71.0 kg (157 lb)
YZ85W1 71.0 kg (157 lb)Engine:Engine type:
Liquid cooled 2-stroke
Cylinder arrangement:
Forward-inclined single cylinder
Displacement:
84.7 cm³ (5.17 cu.in)
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 2-R
Transmission oil:Type:
YAMALUBE 4 (10W30) or SAE10W30 type
SE motor oil
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:Manufacturer:
KEIHIN
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 system:
Spur gear
U5PA85E0.book Page 1 Thursday, April 13, 2006 3:06 PM
SPECIFICATIONS
8-2
8
Primary reduction ratio:
65/18 (3.611)
Secondary reduction system:
Chain drive
Secondary reduction ratio:
YZ85 47/14 (3.357) (ZAF)
YZ85 48/14 (3.428)
(AUT)(BEL)(CHE)(DEU)(DNK)(ESP)(FIN)(
FRA)(GBR)(GRC)(IRL)(NLD)(NOR)(PRT)(
SWE)
YZ85LW 52/14 (3.714)
YZ85LWW 52/14 (3.714)
YZ85W 47/14 (3.357)
YZ85W1 48/14 (3.428)
Transmission type:
Constant mesh 6-speed
Operation:
Left foot operation
Gear ratio:
1st:
27/11 (2.454)
2nd:
32/17 (1.882)
3rd:
26/17 (1.529)
4th:
22/17 (1.294)
5th:
26/23 (1.130)
6th:
25/25 (1.000)Chassis:Frame type:
Semi double cradleCaster angle:
YZ85 26.30 °
YZ85LW 26.90 °
YZ85LWW 26.90 °
YZ85W 26.30 °
YZ85W1 26.30 °
Trail:
YZ85 88.0 mm (3.46 in)
YZ85LW 105.5 mm (4.15 in)
YZ85LWW 105.5 mm (4.15 in)
YZ85W 88.0 mm (3.46 in)
YZ85W1 88.0 mm (3.46 in)
Front tire:Type:
With tube
Size:
YZ85 70/100-17 40M
YZ85LW 70/100-19 42M
YZ85LWW 70/100-19 42M
YZ85W 70/100-17 40M
YZ85W1 70/100-17 40M
Manufacturer/model:
YZ85 DUNLOP/D739FA (ZAF)
YZ85 DUNLOP/D756F
(AUT)(BEL)(CHE)(DEU)(DNK)(ESP)(FIN)(
FRA)(GBR)(GRC)(IRL)(NLD)(NOR)(PRT)(
SWE)
YZ85LW DUNLOP/D756F
YZ85LWW DUNLOP/D756F
YZ85W DUNLOP/D756F
YZ85W1 DUNLOP/D756FRear tire:Type:
With tubeSize:
YZ85 90/100-14 49M
YZ85LW 90/100-16 52M
YZ85LWW 90/100-16 52M
YZ85W 90/100-14 49M
YZ85W1 90/100-14 49M
Manufacturer/model:
DUNLOP/D756
Tire air pressure (measured on cold
tires):
Front:
100 kPa (15 psi) (1.00 kgf/cm²)
Rear:
100 kPa (15 psi) (1.00 kgf/cm²)
Front wheel:Wheel type:
Spoke wheel
Rim size:
YZ85 17x1.40
YZ85LW 19x1.40
YZ85LWW 19x1.40
YZ85W 17x1.40
YZ85W1 17x1.40Rear wheel:Wheel type:
Spoke wheel
Rim size:
YZ85 14x1.60
YZ85LW 16x1.85
YZ85LWW 16x1.85
YZ85W 14x1.60
YZ85W1 14x1.60
U5PA85E0.book Page 2 Thursday, April 13, 2006 3:06 PM
INDEX
AAccessories and replacement parts ..... 6-17
Air filter element, cleaning .................... 6-12BBrake and clutch levers, checking
and lubricating .................................... 6-23
Brake and shift pedals, checking
and lubricating .................................... 6-23
Brake fluid, changing ............................ 6-20
Brake fluid level, checking .................... 6-19
Brake lever ............................................. 3-2
Brake pedal ............................................ 3-2CCables, checking and lubricating .......... 6-22
Carburetor, adjusting ............................ 6-14
Care ........................................................ 7-1
Clutch lever............................................. 3-1
Clutch lever free play, adjusting ........... 6-17
Coolant ................................................. 6-10DDrive chain, cleaning and lubricating .... 6-21
Drive chain slack .................................. 6-20EEngine break-in ...................................... 5-3
Engine, starting a warm .......................... 5-1
Engine stop button.................................. 3-1FFront and rear brake pads, checking .... 6-18
Front fork, adjusting ................................ 3-7
Front fork, bleeding................................. 3-8
Front fork, checking .............................. 6-24
Fuel......................................................... 3-3
Fuel cock ................................................ 3-5
Fuel tank breather hose.......................... 3-5Fuel tank cap........................................... 3-3
HHandlebar switch..................................... 3-1IIdentification numbers ............................. 9-1KKickstarter ............................................... 3-6LLabels, location of ...................................1-4MModel label .............................................. 9-1PParking ....................................................5-4
Part locations .......................................... 2-1
Periodic maintenance and lubrication
chart ......................................................6-2
Pre-operation check list........................... 4-2RRear suspension, lubricating ................. 6-24SSafety information ...................................1-1
Seat ......................................................... 3-6
Shifting ....................................................5-2
Shift pedal ............................................... 3-1
Shock absorber assembly, adjusting ...... 3-9
Sidestand .............................................. 3-12
Spark plug, checking ...............................6-8
Specifications .......................................... 8-1
Starter (choke) knob................................ 3-6
Starting and warming up a cold
engine ................................................... 5-1
Steering, checking.................................6-25
Storage....................................................7-3
Supporting the motorcycle .................... 6-26Swingarm pivots, lubricating ................. 6-24
TThrottle cable free play, adjusting ......... 6-14
Throttle grip and cable, checking
and lubricating .................................... 6-22
Tires ...................................................... 6-15
Transmission oil ...................................... 6-9
Troubleshooting .................................... 6-29
Troubleshooting charts ......................... 6-30VVehicle identification number .................. 9-1WWheel bearings, checking..................... 6-26
Wheel (front) ......................................... 6-27
Wheel (rear) .......................................... 6-27
Wheels .................................................. 6-17
U5PA85E0.book Page 1 Thursday, April 13, 2006 3:06 PM