SAFETY INFORMATION.....................1-1
DESCRIPTION.....................................2-1
Left view ...........................................2-1
Right view .........................................2-2
Controls and instruments .................2-3
INSTRUMENTS AND CONTROL
FUNCTIONS........................................3-1
Main switch/steering lock .................3-1
Indicator and warning lights .............3-2
Speedometer unit .............................3-3
Handlebar switches ..........................3-3
Clutch lever .......................................3-4
Shift pedal.........................................3-4
Brake lever ........................................3-5
Brake pedal.......................................3-5
Fuel tank cap ....................................3-5
Catalytic converter............................3-6
2-stroke engine oil ............................3-7
Fuel cock ..........................................3-7
Starter (choke) lever..........................3-8
Seat...................................................3-8
Shock absorber ................................3-9
YEIS handling precautions ...............3-9
YPVS .................................................3-9
Sidestand ........................................3-10
Ignition circuit cut-off system .........3-10
PRE-OPERATION CHECKS...............4-1
Pre-operation check list....................4-2OPERATION AND IMPORTANT RIDING
POINTS................................................5-1
Starting a cold engine ......................5-1
Starting a warm engine ....................5-2
Shifting ..............................................5-2
Engine break-in.................................5-2
Parking ..............................................5-3
PERIODIC MAINTENANCE AND
MINOR REPAIR...................................6-1
Owner’s tool kit .................................6-1
Periodic maintenance and
lubrication chart ............................6-2
Removing and installing cowlings
and panels .....................................6-5
Checking the spark plug ..................6-6
Transmission oil ................................6-7
Coolant .............................................6-8
Cleaning the air filter element
and check hose ...........................6-10
Ajusting the carburetor ...................6-11
Adjusting the engine idling
speed...........................................6-12
Ajusting the throttle cable free
play ..............................................6-12
Tires ................................................6-13
Spoke wheels .................................6-15
Adjusting the clutch lever free
play ..............................................6-15
Adjusting the brake lever free
play ..............................................6-16Adjusting the brake pedal position
and free play................................6-17
Adjusting the rear brake light
switch ..........................................6-17
Checking the front and rear
brake pads ..................................6-18
Changing the brake fluid ................6-19
Checking the drive chain slack ......6-19
Adjusting the drive chain slack.......6-20
Lubricating the drive chain .............6-20
Checking and lubricating the
cables ..........................................6-21
Checking and lubricating the
throttle grip and cable .................6-21
Adjusting the autolube pump .........6-21
Checking and lubricating the
brake and shift pedals.................6-21
Checking and lubricating the
breake and clutch levers .............6-21
Checking and lubricating the
sidestand .....................................6-21
Checking the front fork ...................6-22
Checking the steering.....................6-22
Checking the wheel bearings .........6-23
Replacing the fuse ..........................6-24
Replacing the headlight bulb..........6-24
Replacing the tail/brake light
bulb .............................................6-25
Replacing the turn signal light
bulb .............................................6-26
Supporting the motorcycle .............6-26
TABLE OF CONTENTS
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EAU10410
Left view
DESCRIPTION
2-1
2
17
28
5
63 4
9
1. Headlight (page 6-24)
2. Radiator cover (page 6-5)
3. Fuel cock (page 3-7)
4. Air filter (page 6-10)
5. Choke lever (page 3-8)
6. Shift pedal (page 3-4)
7. Y.E.I.S (page 3-9)
8. Y.P.V.S. (page 3-9)
9. Oil tank (page 3-7)
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ECA10700
CAUTION
The following precautions must be
observed to prevent a fire hazard or
other damages.
Use only unleaded gasoline.
The use of leaded gasoline will
cause unrepairable damage to
the catalytic converter.
Never park the vehicle near
possible fire hazards such as
grass or other materials that
easily burn.
Do not allow the engine to idle
too long.
EAU13460
2-stroke engine oil
1. Oil tank cap
2. Sensor
Make sure that there is sufficient oil in
the 2-stroke engine oil tank. Add the
recommended 2-stroke engine oil if
necessary.
NOTE:
Make sure that the 2-stroke engine oil
tank cap is properly installed.
Recommended oil:
Yamalube 2 or equivalent 2-stroke
engine oil (JASO grade “FC”, or ISO
grades “EG-C” or “EG-D”)
Oil quantity:
1,3 L (1,37 US qt) (0,29 Imp.qt)
EAU13560
Fuel cock
The fuel cock supplies fuel from the
tank to the carburetor while filtering it
also.
The fuel cock has three positions:OFF
1. Arrow mark
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.
3
INSTRUMENT AND CONTROL FUNCTIONS
3-7
1
211
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EAU17710
Periodic maintenance and lubrication chart
NOTE:
The annual checks must be performed every year, except if a kilometer-based maintenance is performed
instead.
From 30000 km, repeat the maintenance intervals starting from 6000 km.
Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools, data and
technical skills.
PERIODIC MAINTENANCE AND MINOR REPAIR
6-2
6
ODOMETER READING (x 1000 Km) ANNUAL
CHECK
NoITEM CHECK OR MAINTENANCE JOB 1 6 12 18 24
1*Fuel line• Check fuel hoses for cracks or damage.√√√√ √
2Spark plug• Replace.√√√√ √
3Air filter element• Clean.√√• Replace.√√
4Clutch• Check operation.
• Adjust.√√ √ √√
5*Front brake• Check operation, fluid level and vehicle for fluid leakage.√√ √ √√ √• Replace brake pads. Whenever worn to the limit
6*Rear brake• Check operation, fluid level and vehicle for fluid leakage.√√ √ √√ √• Replace brake pads. Whenever worn to the limit
7*Brake hoses• Check for cracks or damage.√√√√ √• Replace. Every 4 years
8*Wheels• Check runout, spoke tightness and for damage.
• Tighten spokes if necessary.√√√√
1D0-F8199-E2.qxd 20/9/04 11:32 Página 33
DimensionsOverall length
DT125RE 2210 mm
DT125X 2139 mm
Overall width
795 mm
Overall height
DT125RE 1200 mm
DT125X 1121 mm
Seat height
DT125RE 900 mm
DT125X 886 mm
Wheelbase
DT125RE 1415 mm
DT125X 1396 mm
Ground clearance
DT125RE 300 mm
DT125X 271 mm
Minimum turning radius
DT125RE 2100 mm
DT125X 2016 mm
WeightWith oil and fuel
DT125RE 126.0 kg
DT125X 134.0 kg
EngineEngine type
Liquid cooled 2-stroke
Cylinder arrangement
Forward-inclined single cylinder
Displacement
124.0 cm
3
Bore x stroke
56.0 x 50.7 mmCompression ratio
6.70 :1
Starting system
Electric starter
Lubrication system
Separate lubrication (Yamaha autolube)
Type
YAMALUBE 2-cycle oil or 2-stroke engine
oil (JASO FC g
Engine oil quantityQuantity
1.3 L
Transmission oilType
SAE10W30 type SE motor oil
Oil change quantity
0.75 L
Cooling systemCoolant reservoir capacity (up to the maxi-
mum leve
0.30 L
Radiator capacity (including all routes)
0.92 L
Air filterAir filter element
Wet element
FuelRecommended fuel
Regular unleaded gasoline only
Fuel tank capacity
10.7 L
Fuel reserve amount
1.8 L
CarburetorManufacturer
MIKUNI
Type x quantity
TM28-92 x1
Spark plug(s)Manufacturer/model
NGK/BR8ES
Spark plug gap
0.7-0.8 mm
Clutch type
Wet, multiple-disc
TransmissionPrimary reduction system
Helical gear
Primary reduction ratio
71/22 (3.227)
Secondary reduction system
Chain drive
Secondary reduction ratio
57/16 (3.563)
Transmission type
Constant mesh 6-speed
Operation
Left foot operation
Gear ratio1st
34/12 (2.833)
2nd
30/16 (1.875)
3rd
24/17 (1.412)
4th
24/21 (1.143)
8
SPECIFICATIONS
8-1
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AAdjusting the autolube pump ..................6-21
Adjusting the brake lever free play ..........6-16
Adjusting the brake pedal position and
free play .................................................6-17
Adjusting the clutch lever free play .........6-15
Adjusting the drive chain slack ................6-20
Adjusting the engine idling speed ...........6-12
Adjusting the rear brake light switch .......6-17
Ajusting the carburetor ............................6-11
Ajusting the throttle cable free play .........6-12
BBrake lever .................................................3-5
Brake pedal ................................................3-5
CCare............................................................7-1
Catalytic converter .....................................3-6
Changing the brake fluid..........................6-19
Checking and lubricating the brake and
shift pedals ............................................6-21
Checking and lubricating the breake and
clutch levers...........................................6-21
Checking and lubricating the cables .......6-21
Checking and lubricating the sidestand ..6-21
Checking and lubricating the throttle grip
and cable ...............................................6-21
Checking the drive chain slack ................6-19
Checking the front and rear brake
pads .......................................................6-18
Checking the front fork ............................6-22
Checking the spark plug ............................6-6
Checking the steering ..............................6-22
Checking the wheel bearings ..................6-23Cleaning the air filter element and check
hose .......................................................6-10
Clutch lever ................................................3-4
Controls and instruments ..........................2-3
Coolant.......................................................6-8
D2-stroke engine oil .....................................3-7
EEngine break-in ..........................................5-2
FFront wheel ..............................................6-26
Fuel cock....................................................3-7
Fuel tank cap .............................................3-5
H
Handlebar switches ...................................3-3
IIdentification numbers ...............................9-1
Ignition circuit cut-off system ..................3-10
Indicator and warning lights ......................3-2
LLeft view .....................................................2-1
Lubricating the drive chain ......................6-20
MMain switch/steering lock ..........................3-1
OOwner’s tool kit ..........................................6-1
PParking .......................................................5-3
Periodic maintenance and lubrication
chart .........................................................6-2
Pre-operation check list .............................4-2
RRear wheel ...............................................6-28Removing and installing cowlings and
panels ......................................................6-5
Replacing the fuse ...................................6-24
Replacing the headlight bulb ...................6-24
Replacing the tail/brake light bulb ...........6-25
Replacing the turn signal light bulb .........6-26
Right view ..................................................2-2
SSeat ............................................................3-8
Shift pedal ..................................................3-4
Shifting .......................................................5-2
Shock absorber..........................................3-9
Sidestand .................................................3-10
Specifications.............................................8-1
Speedometer unit ......................................3-3
Spoke wheels...........................................6-15
Starter (choke) lever ...................................3-8
Starting a cold engine ................................5-1
Starting a warm engine ..............................5-2
Storage.......................................................7-3
Supporting the motorcycle ......................6-26
TTires .........................................................6-13
Transmission oil .........................................6-7
Troubleshooting .......................................6-29
YYEIS handling precautions.........................3-9
YPVS ..........................................................3-9
INDEX
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