FOREWORD
INTRODUCTION
Congratulations on your purchase of
a Yamaha WR series. This model is
the culmination of Yamaha's vast ex-
perience in the production of paceset-
ting racing machines. It represents
the highest grade of craftsmanship
and reliability that have made Yama-
ha a leader.
This manual explains operation, in-
spection, basic maintenance and tun-
ing of your machine. If you have any
questions about this manual or your
machine, please contact your Yama-
ha dealer.
Yamaha continually seeks advance-
ments in product design and quality.
Therefore, while this manual contains
the most current product information
available at the time of printing, there
may be minor discrepancies between
your machine and this manual. If you
have any questions concerning this
manual, please consult your Yamaha
dealer.
PLEASE READ THIS MANUAL
CAREFULLY AND COMPLETELY
BEFORE OPERATING THIS MA-
CHINE. DO NOT ATTEMPT TO OP-
ERATE THIS MACHINE UNTIL YOU
HAVE ATTAINED A SATISFACTO-
RY KNOWLEDGE OF ITS CON-
TROLS AND OPERATING
FEATURES AND UNTIL YOU HAVE
BEEN TRAINED IN SAFE AND
PROPER RIDING TECHNIQUES.
REGULAR INSPECTIONS AND
CAREFUL MAINTENANCE,
ALONG WITH GOOD RIDING
SKILLS, WILL ENSURE THAT YOU
SAFETY ENJOY THE CAPABILI-
TIES AND THE RELIABILITY OF
THIS MACHINE.
PARTICULARLY IMPORTANT
INFORMATION
The Safety Alert Symbol means AT-
TENTION! BECOME ALERT! YOUR
SAFETY IS INVOLVED!
Failure to follow WARNING instruc-
tions could result in severe injury or
death to the machine operator, a by-
stander, or a person inspecting or re-
pairing the machine. A CAUTION indicates special pre-
cautions that must be taken to avoid
damage to the machine.
A NOTE provides key information to
make procedures easier or clearer.
IMPORTANT NOTICE
THIS MACHINE IS DESIGNED
STRICTLY FOR
COMPETITION
USE, ONLY ON A CLOSED
COURSE. It is illegal for this machine
to be operated on any public street,
road, or highway. Off-road use on
public lands may be illegal. Please
check local regulations before riding.
1. THIS MACHINE IS TO BE OP- ERATED BY AN EXPERI-
ENCED RIDER ONLY.
Do not attempt to operate this
machine at maximum power
until you are totally familiar
with its characteristics.
2. THIS MACHINE IS DESIGNED TO BE RIDDEN BY THE OP-
ERATOR ONLY.
Do not carry passengers on
this machine.
3. ALWAYS WEAR PROTEC- TIVE APPAREL.
When operating this ma-
chine, always wear an ap-
proved helmet with goggles
or a face shield. Also wear
heavy boots, gloves, and pro-
tective clothing. Always wear
proper fitting clothing that
will not be caught in any of
the moving parts or controls
of the machine.
4. ALWAYS MAINTAIN YOUR MACHINE IN PROPER
WORKING ORDER.
For safety and reliability, the
machine must be properly
maintained. Always perform
the pre-operation checks in-
dicated in this manual. Cor-
recting a mechanical problem
before you ride may prevent
an accident.
5. GASOLINE IS HIGHLY FLAM- MABLE.
Always turn off the engine
while refueling. Take care to
not spill any gasoline on the
engine or exhaust system.
Never refuel in the vicinity of
an open flame, or while
smoking.
6. GASOLINE CAN CAUSE IN- JURY.
If you should swallow some
gasoline, inhale excess gaso-
line vapors, or allow any gas-
oline to get into your eyes,
contact a doctor immediately.
If any gasoline spills onto
your skin or clothing, imme-
diately wash skin areas with
soap and water, and change
your clothes.
7. ONLY OPERATE THE MA- CHINE IN AN AREA WITH AD-
EQUATE VENTILATION.
Never start the engine or let it
run for any length of time in
an enclosed area. Exhaust
fumes are poisonous. These
fumes contain carbon mon-
oxide, which by itself is odor-
less and colorless. Carbon
monoxide is a dangerous gas
which can cause uncon-
sciousness or can be lethal.
8. PARK THE MACHINE CARE- FULLY; TURN OFF THE EN-
GINE.
Always turn off the engine if
you are going to leave the
machine. Do not park the ma-
chine on a slope or soft
ground as it may fall over.
9. THE ENGINE, EXHAUST PIPE, MUFFLER, AND OIL
TANK WILL BE VERY HOT
AFTER THE ENGINE HAS
BEEN RUN.
Be careful not to touch them
or to allow any clothing item
to contact them during in-
spection or repair.
1-8
CONTROL FUNCTIONS
CONTROL FUNCTIONS
MAIN SWITCH
Functions of the respective switch po-
sitions are as follows:
ON:
The engine can be started only at this
position.
OFF:
All electrical circuits are switched off.
Main switch indicator light
The main switch "1" is equipped with
an indicator light "2" to avoid forget-
ting to turn it off. This light functions
as follows.
• It lights up with the main switch "ON".
• It goes out when the engine in-
creases its speed after being start-
ed.
• It lights up again when the engine is
stopped.
If the indicator light will not light up
with the main switch "ON", it shows a
lack of the battery voltage. Recharge
the battery.
ENGINE STOP SWITCH
The engine stop switch "1" is located
on the left handlebar. Continue push-
ing the engine stop switch till the en-
gine comes to a stop.
START SWITCH
The start switch "1" is located on the
right handlebar. Push this switch to
crank the engine with the starter. CLUTCH LEVER
The clutch lever "1" is located on the
left handlebar; it disengages or en-
gages the clutch. Pull the clutch lever
to the handlebar to disengage the
clutch, and release the lever to en-
gage the clutch. The lever should be
pulled rapidly and released slowly for
smooth starts.
SHIFT PEDAL
The gear ratios of the constant-mesh
5 speed transmission are ideally
spaced. The gears can be shifted by
using the shift pedal "1" on the left
side of the engine.
KICKSTARTER CRANK
Rotate the kickstarter crank "1" away
from the engine. Push the starter
down lightly with your foot until the
gears engage, then kick smoothly
and forcefully to start the engine. This
model has a primary kickstarter crank
so the engine can be started in any
gear if the clutch is disengaged. In
normal practices, however, shift to
neutral before starting.
THROTTLE GRIP
The throttle grip "1" is located on the
right handlebar; it accelerates or de-
celerates the engine. For accelera-
tion, turn the grip
toward you; for
deceleration, turn it away from you. FRONT BRAKE LEVER
The front brake lever "1" is located on
the right handlebar. Pull it toward the
handlebar to activate the front brake.
REAR BRAKE PEDAL
The rear brake pedal "1" is located on
the right side of the machine. Press
down on the brake pedal to activate
the rear brake.
FUEL COCK
The fuel cock supplies fuel from the
tank to carburetor and also filters the
fuel. The fuel cock has the three posi-
tions:
OFF:
With the lever in this position, fuel will
not flow. Always return the lever to
this position when the engine is not
running.
ON:
With the lever in this position, fuel
flows to the carburetor. Normal riding
is done with the lever in this position.
RES:
With the lever in this position fuel
flows to the carburetor from the re-
serve section of the fuel tank after the
main supply of the fuel has been de-
pleted. Normal riding is possible with
the lever is in this position, but it is
recommended to add fuel as soon as
possible.
1-9
MULTI-FUNCTION DISPLAY
COLD STARTER KNOB
When cold, the engine requires a
richer air-fuel mixture for starting. A
separate starter circuit, which is con-
trolled by the cold starter knob "1",
supplies this mixture. Pull the cold
starter knob out to open the circuit for
starting. When the engine has
warmed up, push it in to close the cir-
cuit.
HOT STARTER LEVER
The hot starter lever "1" is used when
starting a warm engine. Use the hot
starter lever when starting the engine
again immediately after it was
stopped (the engine is still warm).
Pulling the hot starter lever injects
secondary air to thin the air-fuel mix-
ture temporarily, allowing the engine
to be started more easily.
SIDESTAND
This sidestand "1" is used to support
only the machine when standing or
transporting it.
• Never apply additional force to the sidestand.
• Hold up the sidestand before
starting out.
MULTI-FUNCTION DISPLAY
Be sure to stop the machine before
making any setting changes to the
multi-function display.
The multi-function display is
equipped with the following:
BASIC MODE:
• Speedometer
•Clock
• Two tripmeters (which shows the distance that has been traveled
since it was last set to zero)
RACE MODE:
• Timer (which shows the time that has been accumulated since the
start of timer measurement)
• Tripmeter (which shows the accu- mulated travel distance in timer
measurement)
• Change tripmeter digits (capable of change to any given ones)
DESCRIPTION
Operation buttons:
1. Select button "SLCT 1"
2. Select button "SLCT 2"
3. Reset button "RST"
Screen display:
4. Tripmeter indicator
5. Tripmeter indicator
6. Timer indicator
7. Clock/Timer
8. Speedometer
9. Odometer/Tripmeter
The operation buttons can be pushed
in the following two manners:
Short push: Push the button. ( )
Long push: Push the button for 2 sec-
onds or more. ( )
BASIC MODE
Changing speedometer display
(for U.K.)
1. Push the "SLCT2" button for 2 seconds or more to change the
speedometer units. The speed-
ometer display will change in the
following order:
MPH →km/h →MPH. Setting the time
1. Push the "SLCT1" button for 2
seconds or more to enter the time
setting mode.
2. Push the "RST" button to change the display for time indication.
The display will change in the fol-
lowing order:
Hour →Minute →Second →Hour.
The digits capable of setting go on
flashing.
3. Push the "SLCT1" button (plus) or
"SLCT2" button (minus) and
change the time. A long push on
the button will fast-forward the
time.
4. To end the setting, push the "RST" button for 2 seconds or
more.
• In a 30-second absence of button operation, the setting will come to
an end with the indicated time.
• To reset the seconds, push the "SLCT1" button or "SLCT2" button.
Changing odometer and tripmeter
A/B (TRIP A/B)
1. Push the "SLCT2" button to change the tripmeter display. The
display will change in the follow-
ing order:
Odometer →TRIP A →TRIP B →
TRIP A →Odometer.
1-10
MULTI-FUNCTION DISPLAY
To reset the digits, select the tripme-
ter involved and push the "RST" but-
ton for 2 seconds or more.
CHANGEOVER TO BASIC MODE/
RACE MODE
• Measurement using the timer func-tion can be made in RACE MODE.
• Indicator will light up as an identifier that shows RACE MODE
has been selected.
• RACE MODE cannot display the functions as in BASIC MODE.
• Changeover to RACE MODE forc- es the digits for tripmeter A (TRIP
A) in BASIC MODE to be reset.
Changeover from BASIC MODE to
RACE MODE
1. Push the "SLCT1" button and "SLCT2" button for 2 seconds or
more at the same time to change
over to RACE MODE.
Changeover to RACE MODE will put
manual start measurement on stand-
by causing and to flash. (For
manual start, refer to "Putting mea-
surement on standby" in "RACE
MODE".)
Returning to BASIC MODE from
RACE MODE
It is possible to return to BASIC
MODE with timer measurement at a
stop.
1. Check that the timer is not in op- eration. If the timer is in operation,
stop the timer by pushing the
"SLCT1" button and "SLCT2" but-
ton at the same time.
2. Push the "SLCT1" button and "SLCT2" button for 2 seconds or
more at the same time to change
over to BASIC MODE.
RACE MODE
Putting measurement on standby
Starting measurement consists of the
following two starts, either of which
can be selected.
• Manual start
Starting measurement by the rider
himself operating the button. (A long
push on the "SLCT2" button will put
measurement on standby.)
• Auto start
Starting timer measurement automat-
ically on detection of the movement of
the machine. (A long push on the
"SLCT1" button will put measurement
on standby.)
Manual start
Initial setting at changeover to RACE
MODE will remain for manual start.
1. Check that changeover to RACE MODE has been made. (Refer to
"Changeover from BASIC MODE
to RACE MODE".)
When the machine is made ready for
a run by manual start, and will
start flashing.
2. Start timer measurement by
pushing the "RST" button.
3. When stopping timer measure- ment, pushing the "SLCT1" but-
ton and "SLCT2" button at the
same time.
If the machine is run while timer mea-
surement is not made, no change will
occur to the digit in tripmeter A (TRIP
A).
4. To resume the measurement,
again push the "SLCT1" button
and "SLCT2" button at the same
time.
Auto start
1. Check that changeover has been made to RACE MODE. (Refer to
"Changeover from BASIC MODE
to RACE MODE".)
2. Make the machine ready for a run
by pushing the "SLCT1" button for
2 seconds or more.
When the measurement is made
ready for a run by auto start, and will start flashing. Timer display
will turn on scrolling from left to right.
3. Run the machine and start timer measurement.
4. To stop timer measurement,
pushing the "SLCT1" button and
"SLCT2" button at the same time.
1-14
STARTING AND BREAK-IN
STARTING AND BREAK-IN
FUEL
Always use the recommended fuel as
stated below. Also, be sure to use
new gasoline the day of a race.
Use only unleaded gasoline. The
use of leaded gasoline will cause
severe damage to the engine inter-
nal parts such as valves, piston
rings, and exhaust system, etc.
If knocking or pinging occurs, use a
different brand of gasoline or higher
octane grade.
• For refueling, be sure to stop the
engine and use enough care not
to spill any fuel. Also be sure to
avoid refueling close to a fire.
• Refuel after the engine, exhaust pipe, etc. have cooled off.
HANDLING NOTE
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 oper-
ate the machine in a well-ventilated
area.
• The carburetor on this machine has a built-in accelerator pump.
Therefore, when starting the en-
gine, do not operate the throttle
or the spark plug will foul.
• Unlike a two-stroke engine, this engine cannot be kick started
when the throttle is open be-
cause the kickstarter may kick
back. Also, if the throttle is open
the air/fuel mixture may be too
lean for the engine to start.
• Before starting the machine, per- form the checks in the pre-opera-
tion check list.
AIR FILTER MAINTENANCE
According to "CLEANING THE AIR
FILTER ELEMENT" section in the
CHAPTER 3, apply the foam-air-filter
oil or its equivalent to the element.
(Excess oil in the element may ad-
versely affect engine starting.)
STARTING A COLD ENGINE
This model is equipped with an igni-
tion circuit cut-off system. The engine
can be started under the following
conditions.
• When the transmission is in neutral.
• When the clutch is disengaged with the transmission in any position.
However, it is recommended to shift
into neutral before starting the en-
gine.
1. Inspect the coolant level.
2. Turn the fuel cock to "ON".
3. Push on the main switch to "ON".
4. Shift the transmission into neutral.
5. Fully open the cold starter knob "1".
6. Start the engine by pushing the start switch or by kicking the kick-
starter crank.
If the engine fails to start by pushing
the start switch, release the switch,
wait a few seconds, and then try
again. Each starting attempt should
be as short as possible to preserve
the battery. Do no t crank the engine
more than 10 seconds on any one at-
tempt. If the engine does not start
with the starter motor, try using the
kickstarter crank.
• If the starter moto r will not turn
when pushing the start switch,
stop pushing it immediately and
kick start the engine in order to
avoid the load on the motor.
• Do not open the throttle while
kicking the kickstarter crank.
Otherwise, the kickstarter crank
may kick back.
7. Return the cold starter knob to its original position and run the en-
gine at 3,000–5,000 r/min for 1 or
2 minutes.
Since this model is equipped with an
accelerator pump, if the engine is
raced (the throttle opened and
closed), the air/fuel mixture will be too
rich and the engine may stall. Also
unlike a two-stroke engine, this model
can idle.
Do not warm up th e engine for ex-
tended periods of time.
STARTING A WARM ENGINE
Do not operate the cold starter knob
and throttle. Pull the hot starter lever
"1" and start the engine by pushing
the start switch or by kicking the kick-
starter crank forcefully with a firm
stroke. As soon as the engine starts,
Release the hot starter lever to close
the air passage.
Restarting an engine after a fall
Pull the hot starter lever and start the
engine. As soon as the engine starts,
Release the hot starter lever to close
the air passage.
Recommended fuel:
Premium unleaded
gasoline only with a re-
search octane number
of 95 or higher.
2-10
MAINTENANCE SPECIFICATIONS
ELECTRICALDrive chain:
Type/manufacturer DID520VM/DAIDO----
Number of links 113 links + joint----
Chain slack 48–58 mm (1.9–2.3 in)----
Chain length (15 links) ----239.3 mm
(9.42 in)
Front disc brake: Disc outside dia.×Thickness 250 × 3.0 mm (9.84 × 0.12 in)250 × 2.5 mm
(9.84 × 0.10 in)
Pad thickness 4.4 mm (0.17 in)1.0 mm (0.04
in)
Master cylinder inside dia. 11.0 mm (0.433 in)----
Caliper cylinder inside dia. 27.0 mm (1.063 in) × 2----
Brake fluid type DOT #4----
Rear disc brake: Disc outside dia.×Thickness 245 × 4.0 mm (9.65 × 0.16 in)245 × 3.5 mm
(9.65 × 0.14 in)
Deflection limit ----0.15 mm
(0.006 in)
Pad thickness 6.4 mm (0.25 in)1.0 mm (0.04
in)
Master cylinder inside dia. 11.0 mm (0.433 in)----
Caliper cylinder inside dia. 25.4 mm (1.000 in) × 1----
Brake fluid type DOT #4----
Brake lever and brake pedal: Brake lever position 95 mm (3.74 in)----
Brake pedal height (vertical height above footrest
top) 10 mm (0.39 in)
----
Clutch lever free play (lever end) 8–13 mm (0.31–0.51 in)----
Throttle grip free play 3–5 mm (0.12–0.20 in)----
Item
StandardLimit
Item StandardLimit
Ignition system: Advancer type Electrical----
CDI: USA, CDN, ZA,
AUS, NZ EUROPE
Pickup coil resistance (color) 248–372 Ωat 20 °C
(68 °F) (White–Red) ←
----
CDI unit-model/manufacturer 5UM-F0/YAMAHA 5UM-L0/YAMAHA ----
Ignition coil: Model/manufacturer 5UL-10/DENSO----
Minimum spark gap 6 mm (0.24 in)----
Primary coil resistance 0.08–0.10 Ωat 20 °C (68 °F) ----
Secondary coil resistance 4.6–6.8 kΩat 20 °C (68 °F) ----
Charging system: System type AC magneto----
Model (stator)/manufacturer 5UM 30/YAMAHA----
2-11
TIGHTENING TORQUES
TIGHTENING TORQUES
ENGINE
△- marked portion shall be checked for torque ti ghtening after break-in or before each race.
Normal output 14 V/120 W at 5,000 r/min----
Charging coil resistance (color) 0.288–0.432 Ω at 20 °C (68 °F) (White–
Ground) ----
Lighting coil resistance (color) 0.224–0.336 Ω at 20 °C (68 °F) (Yellow–
Ground) ----
Rectifier/regulator: Regulator type Semiconductor short circuit----
Model/manufacture SH770AA/SHINDENGEN----
Regulated voltage (AC) 12.5–13.5 V----
Regulated voltage (DC) 14.0–15.0 V----
Rectifier capacity (AC) 12 A----
Rectifier capacity (DC) 8 A----
Electric starting system: Type Constant mesh----
Starter motor: Model/manufacturer 5UM01/YAMAHA----
Operation voltage 12 V----
Output 0.35 kW----
Armature coil resistance 0.0189–0.0231 Ω at 20 °C (68 °F) ----
Brush overall length 7 mm (0.28 in)3.5 mm (0.14
in)
Brush quantity 2 pcs.----
Spring force 3.92–5.88 N (400–600 g, 14.1–21.2 oz) ----
Commutator diameter 17.6 mm (0.69 in)16.6 mm (0.65
in)
Mica undercut (depth) 1.5 mm (0.06 in) ----
Starter relay: Model/manufacturer 2768090-A/JIDECO----
Amperage rating 180 A----
Coil winding resistance 4.2–4.6 Ω at 20 °C (68 °F) ----
Starting circui t cut-off relay:
Model/manufacturer ACM33221 M38/MATSUSHITA ----
Coil winding resistance 75.69–92.51 Ω at 20 °C (68 °F) ----
Fuse (amperage×quantity): Main fuse 10 A × 1----
Reserve fuse 10 A × 1----
Item
StandardLimit
Part to be tightened Thread size Q'tyTightening torque
Nm m•kg ft•lb
Spark plug M10S × 1.0 1 13 1.3 9.4
Camshaft cap M6 × 1.0 10 10 1.0 7.2
Cylinder head blind plug screw M12 × 1.0 1 28 2.8 20
Cylinder head (stud bolt) M6 × 1.0 2 7 0.7 5.1