Yamaha DT125R User manual

PRINTED ON RECYCLED PAPER PRINTED IN JAPAN
2000·12–0.4×1(E) !
OWNER’S MANUAL
3MB-28199-E7
DT125R
YAMAHA MOTOR CO.,LTD.

INTRODUCTION
1
2
4
5
6
7
8
9
EAU00001
Welcome to the Yamaha world of motorcycling!
As the owner of a DT125R, you are benefiting from Yamaha’s vast experience in and newest tech-
nology for the design and the manufacture of high-quality products, which have earned Yamaha a
reputation for dependability.
Please take the time to read this manual thoroughly, so as to enjoy all your DT125R’s advantages.
The owner's manual does not only instruct you in how to operate, inspect and maintain your motorcy-
cle, but also in how to safeguard yourself and others from trouble and injury.
In addition, the many tips given in this manual will help to keep your motorcycle in the best possible
condition. If you have any further questions, do not hesitate to contact your Yamaha dealer.
The Yamaha team wishes you many safe and pleasant rides. So, remember to put safety first!
3MB-9-E7 12/27/00 2:52 PM Page 1

IMPORTANT MANUAL INFORMATION
1
2
3
4
5
6
7
8
9
EAU00005
Particularly important information is distinguished in this manual by the following notations:
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
motorcycle operator, a bystander or a person inspecting or repairing the motorcycle.
A CAUTION indicates special precautions that must be taken to avoid damage to
the motorcycle.
A NOTE provides key information to make procedures easier or clearer.
Q
w
cC
NOTE:
NOTE:
8This manual should be considered a permanent part of this motorcycle and should remain
with it even if the motorcycle is subsequently sold.
8Yamaha continually seeks advancements 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 motorcycle and this manual. If there is any ques-
tion concerning this manual, please consult your Yamaha dealer.
3MB-9-E7 12/27/00 2:52 PM Page 2

IMPORTANT MANUAL INFORMATION
1
2
4
5
6
7
8
9
EW000002
w
PLEASE READ THIS MANUAL CAREFULLY AND COMPLETELY BEFORE OPERATING
THIS MOTORCYCLE.
3MB-9-E7 12/27/00 2:52 PM Page 3

1
2
3
4
5
6
7
8
9
DT125R
OWNER’S MANUAL
© 2000 by Yamaha Motor Co., Ltd.
1st Edition, December 2000
All rights reserved.
Any reprinting or unauthorized use
without the written permission of
Yamaha Motor Co., Ltd.
is expressly prohibited.
Printed in Japan.
EAU03337
3MB-9-E7 12/27/00 2:52 PM Page 4

EAU00009 TABLE OF CONTENTS
1
2
3
4
5
6
7
8
9
GIVE SAFETY THE RIGHT OF WAY..................1-1
DESCRIPTION ....................................................2-1
Left view............................................................2-1
Right view .........................................................2-2
Controls/Instruments.........................................2-3
INSTRUMENT AND CONTROL FUNCTIONS....3-1
Main switch.......................................................3-1
Indicator lights...................................................3-1
Oil level indicator circuit check..........................3-2
Speedometer ....................................................3-3
Tachometer.......................................................3-3
Engine temperature gauge ...............................3-4
Handlebar switches ..........................................3-4
Clutch lever.......................................................3-5
Shift pedal.........................................................3-5
Front brake lever...............................................3-6
Rear brake pedal ..............................................3-6
Fuel tank cap ....................................................3-6
Fuel (except for Switzerland and Austria).........3-7
Fuel (for Switzerland and Austria) ....................3-7
Catalyzer (for Switzerland and Austria) ............3-8
Two-stroke engine oil........................................3-9
Fuel cock ..........................................................3-9
Starter (choke) “1”.........................................3-10
Kick starter......................................................3-11
Steering lock...................................................3-11
Seat ................................................................3-12
Helmet holder .................................................3-12
Rear shock absorber adjustment....................3-13
Rear carrier.....................................................3-14
Note on handling of the Yamaha Energy
Induction System (Y.E.I.S.).............................3-14
Y.P.V.S.
(Yamaha Power Valve System)......................3-15
Sidestand........................................................3-15
Sidestand switch operation check ..................3-16
PRE-OPERATION CHECKS...............................4-1
Pre-operation check list ....................................4-1
OPERATION AND IMPORTANT RIDING
POINTS................................................................5-1
Starting the engine............................................5-1
Starting a warm engine.....................................5-3
Shifting..............................................................5-4
Recommended shift points
(for Switzerland only)........................................5-4
Tips for reducing fuel consumption...................5-5
Engine break-in.................................................5-5
Parking..............................................................5-6
1
2
3
4
5
3MB-9-E7 12/27/00 2:52 PM Page 5

PERIODIC MAINTENANCE AND MINOR
REPAIR................................................................6-1
Tool kit ..............................................................6-1
Periodic maintenance and lubrication chart......6-3
Cowling removal and installation ......................6-6
Cowling A..........................................................6-6
Cowling B..........................................................6-7
Cowling C .........................................................6-8
Panel removal and installation..........................6-8
Panel D.............................................................6-9
Panel E .............................................................6-9
Spark plug.......................................................6-10
Transmission oil..............................................6-11
Cooling system ...............................................6-12
Changing the coolant......................................6-13
Air filter............................................................6-15
Carburetor adjustment....................................6-16
Idle speed adjustment.....................................6-17
Throttle cable free play adjustment.................6-17
Tires................................................................6-18
Wheels............................................................6-20
Clutch lever free play adjustment ...................6-21
Front brake lever free play adjustment ...........6-21
Rear brake pedal height adjustment...............6-22
Brake light switch adjustment .........................6-23
Checking the front and rear brake pads .........6-23
Inspecting the brake fluid level .......................6-24
Brake fluid replacement..................................6-25
Drive chain slack check ..................................6-25
Drive chain slack adjustment..........................6-26
Drive chain lubrication ....................................6-26
Cable inspection and lubrication.....................6-27
Throttle cable and grip lubrication...................6-27
Autolube pump adjustment.............................6-28
Brake and shift pedal lubrication.....................6-28
Brake and clutch lever lubrication...................6-28
Sidestand lubrication ......................................6-29
Front fork inspection .......................................6-29
Steering inspection .........................................6-30
Wheel bearings...............................................6-30
Battery ............................................................6-31
Fuse replacement...........................................6-33
Headlight bulb replacement............................6-33
Turn signal light bulb replacement..................6-35
Tail/brake light bulb replacement....................6-35
Supporting the motorcycle..............................6-36
Front wheel removal .......................................6-36
Front wheel installation...................................6-37
Rear wheel removal........................................6-38
Rear wheel installation....................................6-39
Troubleshooting..............................................6-39
Troubleshooting chart.....................................6-40
TABLE OF CONTENTS
1
2
3
4
5
6
7
8
9
6
3MB-9-E7 12/27/00 2:52 PM Page 6

TABLE OF CONTENTS
1
2
3
4
5
6
7
8
9
MOTORCYCLE CARE AND STORAGE .............7-1
Care..................................................................7-1
Storage .............................................................7-4
SPECIFICATIONS...............................................8-1
How to use the conversion table.......................8-5
CONSUMER INFORMATION..............................9-1
Identification number records ...........................9-1
Key identification number .................................9-1
Vehicle identification number............................9-1
Model label .......................................................9-2
7
8
9
3MB-9-E7 12/27/00 2:52 PM Page 7

1-1
Motorcycles are fascinating vehicles, which can give you an unsurpassed feeling of power and free-
dom. However, they also impose certain limits, which you must accept; even the best motorcycle
does not ignore the laws of physics.
Regular care and maintenance are essential for preserving your motorcycle’s value and operating
condition. Moreover, what is true for the motorcycle is also true for the rider: good performance
depends on being in good shape. Riding under the influence of medication, drugs and alcohol is, of
course, out of the question. Motorcycle riders - more than car drivers - must always be at their mental
and physical best. Under the influence of even small amounts of alcohol, there is a tendency to take
dangerous risks.
Protective clothing is as essential for the motorcycle rider as seat belts are for car drivers and passen-
gers. Always wear a complete motorcycle suit (whether made of leather or tear-resistant synthetic
materials with protectors), sturdy boots, motorcycle gloves and a properly fitting helmet. Optimum pro-
tective wear, however, should not encourage carelessness. Though full-coverage helmets and suits,
in particular, create an illusion of total safety and protection, motorcyclists will always be vulnerable.
Riders who lack critical self-control run the risk of going too fast and are apt to take chances. This is
even more dangerous in wet weather. The good motorcyclist rides safely, predictably and defensively
- avoiding all dangers, including those caused by others.
Enjoy your ride!
EAU00021
QQGIVE SAFETY THE RIGHT OF WAY
1
2
3
4
5
6
7
8
9
3MB-9-E7 12/27/00 2:52 PM Page 8

3MB-9-E7 12/27/00 2:52 PM Page 9

EAU00026
DESCRIPTION
1
2
3
4
5
6
7
8
9
2-1
123 4 5 6
7
8
910
Left view
1. Headlight (page 6-33)
2. Radiator cap (page 6-13)
3. Fuel cock (page 3-9)
4. Air filter (page 6-15)
5. Coolant reservoir tank (page 6-13)
6. Helmet holder (page 3-12)
7. Starter (choke) (page 3-10)
8. Shift pedal (page 3-5, 5-4)
9. Y.E.I.S. (page 3-14)
10. Y.P.V.S. (page 3-15)
3MB-9-E7 12/27/00 2:52 PM Page 10

DESCRIPTION
1
2
3
4
5
6
7
8
9
2-2
11 12 13
1415
Right view
11. Tool kit (page 6-1)
12. Fuse (page 6-33)
13. Engine oil tank (page 3-9)
14. Rear brake pedal (page 3-6, 6-22)
15. Rear shock absorber spring
preload adjusting nut (page 3-13)
3MB-9-E7 12/27/00 2:52 PM Page 11

1
2
3
4
5
6
7
8
9
DESCRIPTION
2-3
16. Clutch lever (page 3-5, 6-21)
17. Left handlebar switches (page 3-4)
18. Speedometer (page 3-3)
19. Coolant temperature gauge (page 3-4)
20. Tachometer (page 3-3)
21. Right handlebar switches (page 3-5)
22. Front brake lever (page 3-6, 6-27)
23. Throttle grip (page 6-17, 6-27)
24. Fuel tank cap (page 3-6)
25. Main switch (page 3-1)
16 17 18 19 20 21 22
2324
25
Controls/Instruments
3MB-9-E7 12/27/00 2:52 PM Page 12

3-1
ON
OFF
EAU00028
Main switch
The main switch controls the ignition
and lighting systems. Its operation is
described below. EAU00036
ON
Electrical circuits are switched on.
The engine can be started. The key
cannot be removed in this position.
EAU00038
OFF
All electrical circuits are switched off.
The key can be removed in this posi-
tion.
EAU00027 INSTRUMENT AND CONTROL FUNCTIONS
1
2
3
4
5
6
7
8
9
EAU00063
High beam indicator light “&”
This indicator comes on when the
headlight high beam is used.
EAU01313
Oil level indicator light “7”
This indicator comes on when the oil
level is low. This light circuit can be
checked by the procedure on page 3-
2. EC000000
cC
Do not run the motorcycle until
you know it has sufficient engine
oil.
NOTE
Even if the oil is filled to the specified
level, the indicator light may flicker
when riding on a slope or during sud-
den acceleration or deceleration, but
this is normal.
123
4
EAU00056
Indicator lights
EAU00057
Turn indicator light “5”
This indicator flashes when the turn
switch is moved to the left or right.
EAU00061
Neutral indicator light “N”
This indicator comes on when the
transmission is in neutral.
1. Turn indicator light “5”
2. High beam indicator light “&”
3. Neutral indicator light “N”
4. Oil level indicator light “7”
3MB-9-E7 12/27/00 2:52 PM Page 13

EAU00075
Oil level indicator circuit check
3-2
INSTRUMENT AND CONTROL FUNCTIONS
1
2
3
4
5
6
7
8
9
Turn the main switch to “ON”.
Put the transmission in neutral.
Oil level indicator light
does not come on.
Ask a Yamaha dealer to
inspect electrical circuit.
Oil level indicator light
comes on.
Oil level indicator light
does not come on.
Supply engine oil.
Shift into gear.
Engine oil level and
electrical circuit are OK.
Go ahead with riding.
Oil level indicator light
comes on.
3MB-9-E7 12/27/00 2:52 PM Page 14

3-3
INSTRUMENT AND CONTROL FUNCTIONS
1
2
3
4
5
6
7
8
9
1
2
1. Tachometer
2. Red zone
EAU00102
Tachometer
This model is equipped with a
tachometer so the rider can monitor
the engine speed and keep it within
the ideal power range.
EC000003
cC
Do not operate in the red zone.
Red zone: 10,500 r/min and above
4
2
3
1
EAU01087
Speedometer
The speedometer shows riding
speed. This speedometer is equipped
with an odometer and trip odometer.
The trip odometer can be reset to “0”
with the reset knob. Use the trip
odometer to estimate how far you
can ride on a tank of fuel. This infor-
mation will enable you to plan fuel
stops in the future.
1. Speedometer
2. Odometer
3. Trip odometer
4. Reset knob
NOTE:
(for German model equipped with
speed limiter only)
This motorcycle is equipped with a
speed limiter which prevents it from
exceeding a top speed of
80 km/h.
3MB-9-E7 12/27/00 2:52 PM Page 15

3-4
INSTRUMENT AND CONTROL FUNCTIONS
1
2
3
4
5
6
7
8
9
EAU00127
Turn signal switch
To signal a right-hand turn, push the
switch to “6”. To signal a left-hand
turn, push the switch to “4”. Once
the switch is released it will return to
the center position. To cancel the sig-
nal, push the switch in after it has
returned to the center position.
EAU00129
Horn switch “*”
Press the switch to sound the horn.
12
1. Coolant temperature gauge
2. Red zone EAU01652
Coolant temperature gauge
This gauge indicates the coolant tem-
perature when the main switch is on.
The engine operating temperature
will vary with changes in weather and
engine load. If the needle points to
the red zone or higher, stop your
motorcycle and let the engine cool.
(See page 6-13 for details.) EC000002
cC
When the engine is overheated, do
not continue riding.
2
1
34
1. Lights switch
2. Dimmer switch
3. Turn signal switch
4. Horn switch “*”EAU00118
Handlebar switches
EAU00134
Lights switch
Turning the light switch to “'”,
turns on the auxiliary light, meter
lights and taillight. Turning the light
switch to “:”, turns the headlight on
also. EAU00121
Dimmer switch
Turn the switch to “&” for the high
beam and to “%” for the low beam.
3MB-9-E7 12/27/00 2:52 PM Page 16

3-5
INSTRUMENT AND CONTROL FUNCTIONS
1
2
3
4
5
6
7
8
9
1
1. Engine stop switch
EAU00138
Engine stop switch
The engine stop switch is a safety
device for use in an emergency such
as when the motorcycle overturns or
if trouble occurs in the throttle sys-
tem. Turn the switch to “#” to start
the engine. In case of emergency,
turn the switch to “$” to stop the
engine.
EAU00155
Clutch lever
The clutch lever is located on the left
handlebar. Pull the clutch lever to the
handlebar to disengage the clutch,
and release the lever to engage the
clutch. The lever should be pulled
rapidly and released slowly for
smooth clutch operation.
6
5
4
3
2
1
N
1
EAU00157
Shift pedal
This motorcycle is equipped with a
constant-mesh 6-speed transmission.
The shift pedal is located on the left
side of the engine and is used in
combination with the clutch when
shifting.
1. Shift pedal
N. Neutral
1
1. Clutch lever
3MB-9-E7 12/27/00 2:52 PM Page 17

3-6
INSTRUMENT AND CONTROL FUNCTIONS
1
2
3
4
5
6
7
8
9
1
1. Front brake lever
EAU00158
Front brake lever
The front brake lever is located on
the right handlebar. Pull it toward the
handlebar to apply the front brake.
1
1. Rear brake pedal
EAU00162
Rear brake pedal
The rear brake pedal is on the right
side of the motorcycle. Press down
on the brake pedal to apply the rear
brake.
3
1
2
EAU00177
Fuel tank cap
To open
Insert the key and turn it 1/4 turn
counterclockwise. Turn the cap 1/3
turn counterclockwise and remove it
from the tank.
To close
Put the cap in the filler neck and turn
it 1/3 turn clockwise. Lock the cap by
turning the key 1/4 turn clockwise,
and remove the key.
1. Fuel tank cap
2. Unlock
3. Open
3MB-9-E7 12/27/00 2:52 PM Page 18

3-7
INSTRUMENT AND CONTROL FUNCTIONS
1
2
3
4
5
6
7
8
9
NOTE:
The tank cap cannot be reinstalled
unless it is unlocked. The key must
remain in the cap until the cap is
properly installed and locked onto the
fuel tank.
EW000023
w
Be sure the cap is properly
installed and locked in place
before riding the motorcycle.
2
1
1. Filler tube
2. Fuel level EAU01183
Fuel
(except for Switzerland and
Austria)
Make sure there is sufficient fuel in
the tank. Fill the fuel tank to the bot-
tom of the filler tube as shown in the
illustration. EW000130
w
Do not overfill the fuel tank. Avoid
spilling fuel on the hot engine. Do
not fill the fuel tank above the bot-
tom of the filler tube or it may
overflow when the fuel heats up
later and expands.
2
1
3
4
1. Filler tube
2. Filling nozzle
3. Leaf valve
4. Fuel level EAU01184
Fuel
(for Switzerland and Austria)
Make sure there is sufficient fuel in
the tank. When refueling, be sure to
insert the filling nozzle into the filler
hole and fill the tank to the bottom of
the filler tube as shown in the illustra-
tion.
3MB-9-E7 12/27/00 2:52 PM Page 19