warning YAMAHA YZ85 2003 Owners Manual

EC020000
INTRODUCTION
Congratulations on your purchase of a
Yamaha YZ series. This model is the culmina-
tion of Yamaha’s vast experience in the pro-
duction of pacesetting racing machines. It
represents the highest grade of craftsmanship
and reliability that have made Yamaha a
leader.
This manual explains operation, inspection,
basic maintenance and tuning of your
machine. If you have any questions about this
manual or your machine, please contact your
Yamaha dealer.
NOTE:
As improvements are made on this model,
some data in this manual may become out-
dated. If you have any questions, please con-
sult your Yamaha dealer.
WARNING
PLEASE READ THIS MANUAL CAREFULLY
AND COMPLETELY BEFORE OPERATING
THIS MACHINE. DO NOT ATTEMPT TO
OPERATE THIS MACHINE UNTIL YOU
HAVE ATTAINED A SATISFACTORY
KNOWLEDGE OF ITS CONTROLS AND
OPERATING FEATURES AND UNTIL YOU
HAVE BEEN TRAINED IN SAFE AND
PROPER RIDING TECHNIQUES. REGULAR
INSPECTIONS AND CAREFUL MAINTE-
NANCE, ALONG WITH GOOD RIDING
SKILLS, WILL ENSURE THAT YOU SAFETY
ENJOY THE CAPABILITIES AND THE RELI-
ABILITY OF THIS MACHINE.

EC080000
HOW TO USE
THIS MANUAL
EC081000
PARTICULARLY IMPORTANT
INFORMATION
The Safety Alert Symbol means ATTENTION!
BECOME ALERT! YOUR SAFETY IS
INVOLVED!
Failure to follow WARNING instructions could
result in severe injury or death to the machine
operator, a bystander, or a person inspecting
or repairing the machine.
A CAUTION indicates special precautions that
must be taken to avoid damage to the
machine.
NOTE:
A NOTE provides key information to make pro-
cedures easier or clearer.
WARNING
CAUTION:
EC082000
FINDING THE REQUIRED PAGE
1. This manual consists of seven chapters;
“General information”, “Specifications”,
“Regular inspection and adjustments”,
“Engine”, “Chassis”, “Electrical” and “Tun-
ing”.
2. The table of contents is at the beginning of
the manual. Look over the general layout of
the book before finding then required chap-
ter and item.
Bend the book at its edge, as shown, to
find the required fore edge symbol mark
and go to a page for required item and
description.
5PA00010

1 - 11
GEN
INFO
CONTROL FUNCTIONS
EC15F000
VALVE JOINT
This valve joint 1 prevents fuel from flowing
out and is installed to the fuel tank breather
hose.
CAUTION:
In this installation, make sure the arrow
faces the fuel tank and also downward.
5PA10510
EC15R001
DETACHABLE SIDESTAND
This sidestand 1 is used to support only the
machine when standing or transporting it.
WARNING

Never apply additional force to the side-
stand.

Remove this sidestand before starting
out.
NIPPLE WRENCH
This nipple wrench 1 is used to tighten the
spoke.5PA10520
5PA10530
AIR FILTER CASE COVER
In order to prevent water from entering the car-
buretor while the machine is operated in the
rain, attach the air filter case cover 1 to the
rear frame.

Air filter case cover installation
1. Set the air filter case cover as shown, and
install it to the seat rail of the rear frame
while rotating air filter case cover in the
direction of the arrow.
2. Using a conventional screwdriver, hold up
the front of the air filter case cover.
Then engage the groove a in the cover
over the air filter case edge b.
5PA10530
5PA10530

1 - 13
GEN
INFO
STARTING AND BREAK-IN
STARTING AND BREAK-IN
CAUTION:
Before starting the machine, perform the
checks in the pre-operation check list.
WARNING
Never start or run the engine in a closed
area. The exhaust fumes are poisonous;
they can cause loss of consciousness and
death in a very short time. Always operate
the machine in a well-ventilated area.
STARTING A COLD ENGINE
1. Shift the transmission into neutral.
2. Turn the fuel cock to “ON” and full open the
starter knob (CHOKE).
3. With the throttle completely closed start the
engine by kicking the kickstarter crank
forthly with firm stroke.
4. Run the engine at idle or slightly higher
until it warms up: this usually takes about
one or two minutes.
5. The engine is warmed up when it responds
normally to the throttle with the starter knob
(CHOKE) turned off.
CAUTION:
Do not warm up the engine for extended
periods.
STARTING A WARM ENGINE
Do not operate the starter knob (CHOKE).
Open the throttle slightly and start the engine
by kicking the kickstarter crank forcefully with
firm stroke.
CAUTION:
Observe the following break-in procedures
during initial operation to ensure optimum
performance and avoid engine damage.

3 - 5
INSP
ADJ
EC350000
ENGINE
COOLANT LEVEL INSPECTION
WARNING
Do not remove the radiator cap
1, drain
bolt and hoses when the engine and radia-
tor are hot. Scalding hot fluid and steam
may be blown out under pressure, which
could cause serious injury.
When the engine has cooled, place a thick
towel over the radiator cap, slowly rotate
the cap counterclockwise to the detent.
This procedure allows any residual pres-
sure to escape. When the hissing sound
has stopped, press down on the cap while
turning counterclockwise and remove it.
CAUTION:
Hard water or salt water is harmful to the
engine parts. You may use distilled water, if
you can’t get soft water.
5PA30010
1. Place the machine on a level place, and
hold it in an upright position.
2. Remove:

Radiator cap
3. Check:

Coolant level
Coolant level a low → Add coolant.
1Radiator
5PA30020
ENGINE/COOLANT LEVEL INSPECTION

3 - 6
INSP
ADJ
COOLANT REPLACEMENT
COOLANT REPLACEMENT
WARNING
Do not remove the radiator cap when the
engine is hot.
CAUTION:
Take care so that coolant does not splash
on painted surfaces. If it splashes, wash it
away with water.
1. Place a container under the engine.
2. Remove:

Coolant drain bolt 1
3. Remove:

Radiator cap
Drain the coolant completely.
4. Clean:

Cooling system
Thoroughly flush the cooling system with
clean tap water.
5. Install:

Copper washer

Coolant drain bolt
5PA30030
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
6. Fill:

Radiator

Engine
To specified level.
Recommended coolant:
High quality ethylene glycol
anti-freeze containing anti-
corrosion for aluminum engine
Coolant
1 and water (soft water)
2
mixing ratio:
50 %/50 %
Coolant capacity:
0.54 L (0.48 Imp qt, 0.57 US qt)
5PA30040

3 - 7
INSP
ADJ
RADIATOR CAP INSPECTION
CAUTION:

Do not mix more than one type of ethyl-
ene glycol antifreeze containing corro-
sion inhibitors for aluminum engine.

Do not use water containing impurities or
oil.
7. Install:

Radiator cap
Start the engine and warm it up for a sev-
eral minutes.
8. Check:

Coolant level
Coolant level low → Add coolant. Handling notes of coolant:
The coolant is harmful so it should be han-
dled with special care.
WARNING

When coolant splashes to your eye.
Thoroughly wash your eye with water
and see your doctor.

When coolant splashes to your clothes.
Quickly wash it away with water and
then with soap.

When coolant is swallowed.
Quickly make him vomit and take him
to a doctor.
EC355000
RADIATOR CAP INSPECTION
1. Inspect:

Seal (radiator cap) 1

Valve and valve seat 2
Crack/damage → Replace.
Exist fur deposits 3 → Clean or replace.
5PA30050

3 - 10
INSP
ADJTHROTTLE CABLE ADJUSTMENT/
THROTTLE LUBRICATION
EC35A001
THROTTLE CABLE ADJUSTMENT
1. Check:

Throttle grip free play a
Out of specification → Adjust.
Throttle grip free play
a:
3 ~ 5 mm (0.12 ~ 0.20 in)
5PA30110
2. Adjust:

Throttle grip free play
Throttle grip free play adjustment steps:

Loosen the locknut 1.

Turn the adjuster 2 until the specified free
play is obtained.

Tighten the locknut.
NOTE:
Before adjusting the throttle cable free play,
the engine idle speed should be adjusted.
WARNING
After adjusting, turn the handlebar to
right and left and make sure that the
engine idling does not run faster.
5PA30120
THROTTLE LUBRICATION
1. Remove:

Throttle cable cap 1
5PA30130
2. Apply:

Lithium soap base grease
On the throttle cable end a and tube guide
cable winding portion b.
3. Install:

Throttle grip cap
5PA30140
T R..1 Nm (0.1 m · kg, 0.7 ft · lb)

3 - 16
INSP
ADJ
CHASSIS/BRAKE SYSTEM AIR BLEEDING
EC360000
CHASSIS
EC361012
BRAKE SYSTEM AIR BLEEDING
WARNING
Bleed the brake system if:

The system has been disassembled.

A brake hose has been loosened or
removed.

The brake fluid is very low.

The brake operation is faulty.
A dangerous loss of braking performance
may occur if the brake system is not prop-
erly bleed.
1. Remove:

Reservoir cap

Diaphragm
2. Bleed:

Brake fluid
ÈFront
ÉRear
Air bleeding steps:
a. Add proper brake fluid to the reservoir.
b. Install the diaphragm. Be careful not to
spill any fluid or allow the reservoir to
overflow.
c. Connect the clear plastic tube 2 tightly to
the caliper bleed screw 1.
d. Place the other end of the tube into a con-
tainer.
e. Slowly apply the brake lever or pedal sev-
eral times.
f. Pull the lever in or push down on the
pedal. Hold the lever or pedal in position.
g. Loosen the bleed screw and allow the
lever or pedal to travel towards its limit.
h. Tighten the bleed screw when the lever or
pedal limit has been reached; then
release the lever or pedal.
T R..
Bleed screw:
6 Nm (0.6 m  kg, 4.3 ft  lb)
i. Repeat steps (e) to (h) until of the air bub-
bles have been removed from the system.
È
5PA30290
É
5PA30300

3 - 17
INSP
ADJ
FRONT BRAKE ADJUSTMENT
3. Install:

Diaphragm

Reservoir cap NOTE:
If bleeding is difficult, it may be necessary to
let the brake fluid system stabilize for a few
hours. Repeat the bleeding procedure when
the tiny bubbles in the system have disap-
peared.
j. Add brake fluid to the level line on the res-
ervoir.
WARNING
Check the operation of the brake after
bleeding the brake system.
EC362040
FRONT BRAKE ADJUSTMENT
1. Check:

Brake lever position a
2. Remove:

Lever cover
3. Adjust:

Brake lever position
4. Install:

Lever cover
Standard brake lever position:
95 mm (3.74 in)
Extent of adjustment:
76 ~ 97 mm (2.99 ~ 3.82 in)
Brake lever position adjustment steps:

Loosen the locknut 1.

Turn the adjusting bolt 2 until the lever
position a is within specified position.

Tighten the locknut.
T R..
Locknut:
5 Nm (0.5 m  kg, 3.6 ft  lb)
CAUTION:
Be sure to tighten the locknut, as it will
cause poor brake performance.
5PA30310
5PA30320