• Bulky or large accessories may
seriously affect the stability of
the motorcycle due to aerody-
namic effects. Wind may
attempt to lift the motorcycle,
or the motorcycle may become
unstable in cross winds. These
accessories may also cause
instability when passing or
being passed by large vehicles.
• Certain accessories can dis-
place the operator from his or
her normal riding position. This
improper position limits the fre-
edom of movement of the ope-
rator and may limit control abi-
lity, therefore, such
accessories are not recom-
mended.
Use caution when adding electri-
cal accessories. If electrical
accessories exceed the capacity
of the motorcycle’s electrical sys-
tem an electric failure could
result, which could cause a dan-
gerous loss of lights or engine
power.Gasoline and exhaust gas
GASOLINE IS HIGHLY FLAMMA-
BLE:
• Always turn the engine off
when refueling.
• Take care not to spill any gaso-
line on the engine or exhaust
system when refueling.
• Never refuel while smoking or
in the vicinity of an open flame.
Never start the engine or let it run
for any length of time in a closed
area. The exhaust fumes are poi-
sonous and may cause loss of
consciousness and death within
a short time. Always operate your
motorcycle in an area that has
adequate ventilation.
Always turn the engine off before
leaving the motorcycle unatten-
ded and remove the key from the
main switch. When parking the
motorcycle, note the following:
• The engine and exhaust sys-
tem may be hot, therefore,
park the motorcycle in a place
where pedestrians or children
are not likely to touch these hot
areas.• Do not park the motorcycle on
a slope or soft ground, other-
wise it may fall over.
• Do not park the motorcycle
near a flammable source (e.g.,
a kerosene heater, or near an
open flame), otherwise it could
catch fire.
When transporting the motorcy-
cle in another vehicle, make sure
that it is kept upright and that the
fuel cock(s) are turned to “ON” or
“RES” (for vacuum type)/”OFF”
(for manual type). If the motorcy-
cle should lean over, gasoline
may leak out of the carburetor or
fuel tank.
If you should swallow any gasoli-
ne, inhale a lot of gasoline vapor,
or allow gasoline to get into your
eyes, see your doctor immedia-
tely. If any gasoline spills on your
skin or clothing, immediately
wash the affected area with soap
and water and change your clot-
hes.
1
SAFETY INFORMATION t
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2. Hold the lower ends of the front
fork legs and try to move them
forward and backward. If any free
play can be felt, have a Yamaha
dealer check or repair the stee-
ring.
EAU23290
Checking the wheel bearings
The front and rear wheel bearings
must be checked at the intervals spe-
cified in the periodic maintenance and
lubrication 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.
EAU23380
Battery
1. Battery
2. Battery ventilation pipe
The battery is located behind panel D.
(See page 6-6.)
This model is equipped with a sealed-
type (MF) battery, which does not
require any maintenance. There is no
need to check the electrolyte or to
add distilled water.
ECA10620
CAUTION
Never attempt to remove the bat-
tery cell seals, as this would per-
manently damage the battery.
EWA10760
s s
WARNING
Electrolyte is poisonous and
dangerous since it contains
sulfuric acid, which causes
severe burns. Avoid any con-
tact with skin, eyes or clothing
and always shield your eyes
when working near batteries.
In case of contact, administer
the following FIRST AID.
• EXTERNAL: Flush with plenty
of water.
• INTERNAL: Drink large quan-
tities of water or milk and
immediately call a physician.• EYES: Flush with water for 15
minutes and seek prompt
medical attention.
• Batteries produce explosive
hydrogen gas. Therefore,
keep sparks, flames, cigaret-
tes, etc., away from the bat-
tery and provide sufficient
ventilation when charging it
in an enclosed space.
KEEP THIS AND ALL BATTE-
RIES OUT OF THE REACH OF
CHILDREN.
To charge the battery
Have a Yamaha dealer charge the
battery as soon as possible if it seems
to have discharged. Keep in mind that
the battery tends to discharge more
quickly if the vehicle is equipped with
optional electrical accessories.
To store the battery
1. If the vehicle will not be used for
more than one month, remove
the battery, fully charge it, and
then place it in a cool, dry place.
6
PERIODIC MAINTENANCE AND MINOR REPAIR
6-23
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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
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5th
22/23 (0.957)
6th
18/22 (0.818)
ChassisFrame type
Semi double cradle
Caster angle
DT125RE 27.00 degree
DT125X 24.50 degree
Trail
DT125RE 107.0 mm
DT125X 73.1 mm
Front tireType
With tube
Size
DT125RE 80/90-21 48P
DT125X 120/70-17 58H
Manufacturer/model
DT125RE MICHELIN/T63
DT125X PIRELLI/Sport Demon
Rear tireType
With tube
Size
DT125RE 110/80-18 58P
DT125X 140/70-17 66H
Manufacturer/model
DT125RE MICHELIN/T63
DT125X PIRELLI/Sport Demon
Maximum load
DT125RE 178 kg
DT125X 180 kg
Tire air pressure (measured on cold
tires)
Loading condition
0-90 kg
Front
DT125RE 150 kPa
DT125X 180 kPa
Rear
DT125RE 175 kPa
DT125X 200 kPa
Loading condition
90-178 kg
Front
DT125RE 175 kPa
DT125X 180 kPa
Rear
200 kPa
Off-road ridingFront
DT125RE 150 kPa
Rear
DT125RE 175 kPa
Front wheelWheel type
Spoke wheel
Rim size
DT125RE 21x1.60
DT125X 17x3.00
Rear wheelWheel type
Spoke wheel
Rim size
DT125RE 18x1.85
DT125X 17x3.50
Front brakeType
Single disc brake
Operation
Right hand operation
Recommended fluid
DOT 4
Rear brakeType
Single disc brake
Operation
Right foot operation
Recommended fluid
DOT 4
Front suspensionType
Telescopic fork
Spring/shock absorber type
Coil spring/oil damper
Wheel travel
DT125RE 270.0 mm
DT125X 200.0 mm
Rear suspensionType
Swingarm (link suspension)
Spring/shock absorber type
Coil spring/gas-oil damper
Wheel travel
DT125RE 260.0 mm
DT125X 230.0 mm
Electrical systemIgnition system
CDI
8
SPECIFICATIONS
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