2008 YAMAHA YZ85 engine

PERIODIC MAINTENANCE AND MINOR REPAIR
6-27
6
EAU23290
Checking the wheel bearings The front and rear wheel bearings must
be checked at the intervals specified in
the periodic maintenance and lubrica-
tion chart. If there is play in the wheel
hub or if the wheel does not turn
smoothly, have a Yamaha dealer check
the wheel bearings.
EAU24350
Supporting the motorcycle Since this model is not equipped with a
centerstand, follow these precautions
when removing the front and rear
wheel or performing other maintenance
requiring the motorcycle to stand up-
right. Check that the motorcycle is in a
stable and level position before starting
any maintenance. A strong wooden
box can be placed under the engine for
added stability.
To service the front wheel
1. Stabilize the rear of the motorcycle
by using a motorcycle stand or, if
an additional motorcycle stand is
not available, by placing a jack un-
der the frame in front of the rear
wheel.
2. Raise the front wheel off the
ground by using a motorcycle
stand.
To service the rear wheel
Raise the rear wheel off the ground by
using a motorcycle stand or, if a motor-
cycle stand is not available, by placinga jack either under each side of the
frame in front of the rear wheel or under
each side of the swingarm.
U5PA86E0.book Page 27 Monday, April 9, 2007 3:16 PM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-31
6
EAU41491
Troubleshooting charts Starting problems or poor engine performance
WARNING
EWA10840
Keep away open flames and do not smoke while checking or working on the fuel system.
Check the fuel level in
the fuel tank.1. Fuel
There is
enough fuel.
There is
no fuel.
Supply fuel.
Operate the kickstarter.2. Compression
There is compression.
There is
no compression.Check the ignition.
Have a Yamaha dealer
check the vehicle.
Remove the spark plug
and check the electrodes.3. Ignition
Wet
DryWipe off with a dry cloth and correct the
spark plug gap, or replace the spark plug.
Have a Yamaha dealer check the vehicle.The engine does not start.
Have a Yamaha dealer check the vehicle.
Open the throttle halfway and operate
the kickstarter.
Check the compression.
The engine does not start.
Check the compression.
U5PA86E0.book Page 31 Monday, April 9, 2007 3:16 PM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-32
6Engine overheating
WARNING
EWAT1040


Do not remove the radiator cap when the engine and radiator are hot. Scalding hot fluid and steam may be
blown out under pressure, which could cause serious injury. Be sure to wait until the engine has cooled.


Place a thick rag, like a towel, over the radiator cap, and then slowly rotate the cap counterclockwise to the de-
tent to allow any residual pressure to escape. When the hissing sound has stopped, press down on the capwhile turning it counterclockwise, and then remove the cap.
NOTE:If coolant is not available, tap water can be temporarily used instead, provided that it is changed to the recommended coolantas soon as possible.
Wait until the
engine has cooled.
Check the coolant level in the
radiator.
The coolant level
is OK.The coolant level is low.
Check the cooling system
for leakage.
Have a Yamaha dealer checkand repair the cooling system.Add coolant. (See NOTE.)
Start the engine. If the engine overheats again,
have a
Yamaha dealer check
and repair the cooling system.
There is
leakage.
There is
no leakage.
U5PA86E0.book Page 32 Monday, April 9, 2007 3:16 PM

MOTORCYCLE CARE AND STORAGE
7-1
7
EAU37833
Matte color caution CAUTION:
ECA15192
Some models are equipped with
matte colored finished parts. Be
sure to consult a Yamaha dealer for
advice on what products to use be-
fore cleaning the vehicle. Using a
brush, harsh chemical products or
cleaning compounds when cleaning
these parts will scratch or damage
their surface. Wax also should not
be applied to any matte colored fin-ished parts.
EAU41352
Care While the open design of a motorcycle
reveals the attractiveness of the tech-
nology, it also makes it more vulnera-
ble. Rust and corrosion can develop
even if high-quality components are
used. A rusty exhaust pipe may go un-
noticed on a car, however, it detracts
from the overall appearance of a motor-
cycle. Frequent and proper care does
not only comply with the terms of the
warranty, but it will also keep your
motorcycle looking good, extend its life
and optimize its performance.
Before cleaning
1. Cover the muffler outlet with a
plastic bag after the engine has
cooled down.
2. Make sure that all caps and covers
as well as all electrical couplers
and connectors, including the
spark plug cap, are tightly in-
stalled.
3. Remove extremely stubborn dirt,
like oil burnt onto the crankcase,
with a degreasing agent and a
brush, but never apply such prod-ucts onto seals, gaskets, sprock-
ets, the drive chain and wheel
axles. Always rinse the dirt and de-
greaser off with water.
Cleaning
CAUTION:
ECA10771


Avoid using strong acidic wheel
cleaners, especially on spoked
wheels. If such products are
used on hard-to-remove dirt, do
not leave the cleaner on the af-
fected area any longer than in-
structed. Also, thoroughly rinse
the area off with water, immedi-
ately dry it, and then apply a cor-
rosion protection spray.


Improper cleaning can damage
plastic parts such as cowlings,
panels, windshields, headlight
lenses, meter lenses, etc. Use
only a soft, clean cloth or
sponge with mild detergent and
water to clean plastic.


Do not use any harsh chemical
products on plastic parts. Be
sure to avoid using cloths or
sponges which have been in
U5PA86E0.book Page 1 Monday, April 9, 2007 3:16 PM

MOTORCYCLE CARE AND STORAGE
7-2
7contact with strong or abrasive
cleaning products, solvent or
thinner, fuel (gasoline), rust re-
movers or inhibitors, brake flu-
id, antifreeze or electrolyte.


Do not use high-pressure wash-
ers or steam-jet cleaners since
they cause water seepage and
deterioration in the following ar-
eas: seals (of wheel and swing-
arm bearings, fork and brakes),
electric components (couplers,
connectors, instruments,
switches and lights), breather
hoses and vents.


For motorcycles equipped with
a windshield: Do not use strong
cleaners or hard sponges as
they will cause dulling or
scratching. Some cleaning com-
pounds for plastic may leave
scratches on the windshield.
Test the product on a small hid-
den part of the windshield to
make sure that it does not leave
any marks. If the windshield isscratched, use a quality plastic
polishing compound after
washing.
After normal use
Remove dirt with warm water, a mild
detergent, and a soft, clean sponge,
and then rinse thoroughly with clean
water. Use a toothbrush or bottlebrush
for hard-to-reach areas. Stubborn dirt
and insects will come off more easily if
the area is covered with a wet cloth for
a few minutes before cleaning.
After riding in the rain or near the seaSince sea salt is extremely corrosive,
carry out the following steps after each
ride in the rain or near the sea.
1. Clean the motorcycle with cold wa-
ter and a mild detergent, after the
engine has cooled down.CAUTION:
ECA10790
Do not use warm water since it in-
creases the corrosive action of thesalt.
2. Apply a corrosion protection spray
on all metal, including chrome- and
nickel-plated, surfaces to prevent
corrosion.After cleaning
1. Dry the motorcycle with a chamois
or an absorbing cloth.
2. Immediately dry the drive chain
and lubricate it to prevent it from
rusting.
3. Use a chrome polish to shine
chrome, aluminum and stainless-
steel parts, including the exhaust
system. (Even the thermally in-
duced discoloring of stainless-
steel exhaust systems can be re-
moved through polishing.)
4. To prevent corrosion, it is recom-
mended to apply a corrosion pro-
tection spray on all metal,
including chrome- and nickel-plat-
ed, surfaces.
5. Use spray oil as a universal clean-
er to remove any remaining dirt.
6. Touch up minor paint damage
caused by stones, etc.
7. Wax all painted surfaces.
8. Let the motorcycle dry completely
before storing or covering it.
WARNING
EWA11130


Make sure that there is no oil or
wax on the brakes or tires.
U5PA86E0.book Page 2 Monday, April 9, 2007 3:16 PM

MOTORCYCLE CARE AND STORAGE
7-3
7


If necessary, clean the brake
discs and brake linings with a
regular brake disc cleaner or ac-
etone, and wash the tires with
warm water and a mild deter-
gent. Before riding at higher
speeds, test the motorcycle’s
braking performance and cor-nering behavior.
CAUTION:
ECA10800


Apply spray oil and wax spar-
ingly and make sure to wipe off
any excess.


Never apply oil or wax to any
rubber and plastic parts, but
treat them with a suitable care
product.


Avoid using abrasive polishing
compounds as they will wearaway the paint.
NOTE:Consult a Yamaha dealer for advice onwhat products to use.
EAU41511
Storage Short-term
Always store your motorcycle in a cool,
dry place and, if necessary, protect it
against dust with a porous cover.CAUTION:
ECA10810


Storing the motorcycle in a
poorly ventilated room or cover-
ing it with a tarp, while it is still
wet, will allow water and humid-
ity to seep in and cause rust.


To prevent corrosion, avoid
damp cellars, stables (because
of the presence of ammonia)
and areas where strong chemi-cals are stored.
Long-term
Before storing your motorcycle for sev-
eral months:
1. Follow all the instructions in the
“Care” section of this chapter.
2. For motorcycles equipped with a
fuel cock that has an “OFF” posi-
tion: Turn the fuel cock lever to
“OFF”.3. Drain the fuel tank and fuel lines,
and the carburetor float chamber
by loosening the drain bolt; this will
prevent fuel deposits from building
up.
4. Perform the following steps to pro-
tect the cylinder, piston rings, etc.
from corrosion.
a. Remove the spark plug cap
and spark plug.
b. Pour a teaspoonful of engine oil
into the spark plug bore.
c. Install the spark plug cap onto
the spark plug, and then place
the spark plug on the cylinder
head so that the electrodes are
grounded. (This will limit spark-
ing during the next step.)
d. Turn the engine over several
times with the starter. (This will
coat the cylinder wall with oil.)
e. Remove the spark plug cap
from the spark plug, and then
install the spark plug and the
spark plug cap.
U5PA86E0.book Page 3 Monday, April 9, 2007 3:16 PM

MOTORCYCLE CARE AND STORAGE
7-4
7
WARNING
EWA10950
To prevent damage or injury from
sparking, make sure to ground the
spark plug electrodes while turningthe engine over.
5. Lubricate all control cables and the
pivoting points of all levers and
pedals.
6. Check and, if necessary, correct
the tire air pressure, and then lift
the motorcycle so that both of its
wheels are off the ground. Alterna-
tively, turn the wheels a little every
month in order to prevent the tires
from becoming degraded in one
spot.
7. Cover the muffler outlet with a
plastic bag to prevent moisture
from entering it.NOTE:Make any necessary repairs beforestoring the motorcycle.U5PA86E0.book Page 4 Monday, April 9, 2007 3:16 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)
YZ85LWX 1903 mm (74.9 in)
YZ85X 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)
YZ85LWX 1205 mm (47.4 in)
YZ85X 1161 mm (45.7 in)
Seat height:
YZ85 864 mm (34.0 in)
YZ85LW 904 mm (35.6 in)
YZ85LWX 904 mm (35.6 in)
YZ85X 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)
YZ85LWX 1286 mm (50.6 in)
YZ85X 1255 mm (49.4 in)Ground clearance:
YZ85 351 mm (13.82 in)
YZ85LW 393 mm (15.47 in)
YZ85LWX 393 mm (15.47 in)
YZ85X 351 mm (13.82 in)
Weight:With oil and fuel:
YZ85 71.0 kg (157 lb)
YZ85LW 73.9 kg (163 lb)
YZ85LWX 73.9 kg (163 lb)
YZ85X 71.0 kg (157 lb)Engine:Engine type:
Liquid cooled 2-stroke
Cylinder arrangement:
Forward-inclined single cylinder
Displacement:
84.7 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 2-RTransmission oil:Type:
YAMALUBE 4 (10W30) or SAE 10W30
type SE motor oilOil 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
Primary reduction ratio:
65/18 (3.611)
Secondary reduction system:
Chain drive
U5PA86E0.book Page 1 Monday, April 9, 2007 3:16 PM