• 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
1-4
1D0-F8199-E2.qxd 20/9/04 11:32 Página 11
stop the engine in case of an emer-
gency, such as when the motorcycle
overturns or when the throttle cable is
stuck.
EAU12710
Start switch “g”
Push this switch to crank the engine
with the starter.
ECA10050
CAUTION
See page 5-1 for starting instruc-
tions prior to starting the engine.
EAU12763
Hazard switch “ ”
With the key in the “ON” position, turn
this switch to “ ” to turn on the
hazard lights (simultaneous flashing
of all turn signal lights).
The hazard lights are used in case of
an emergency or to warn other drivers
when your vehicle is stopped where it
might be a traffic hazard.
ECA10060
CAUTION
Do not use the hazard light for an
extended length of time, otherwi-
sethe battery may discharge.
EAU12820
Clutch lever
1. Clutch lever
The clutch lever is located at the left
handlebar grip. To disengage the
clutch, pull the lever toward the hand-
lebar grip. To engage the clutch, rele-
ase the lever. The lever should be
pulled rapidly and released slowly for
smooth clutch operation.
The clutch lever is equipped with a
clutch switch, which is part of the
ignition circuit cut-off system. (See
page 3-11.)
EAU12880
Shift pedal
N. Neutral
1. Shift pedal
The shift pedal is located on the left
side of the engine and is used in com-
bination with the clutch lever when
shifting the gears of the 6-speed
constant-mesh transmission equip-
ped on this motorcycle.
NOTE:
Use your toes or heel to shift up and
your toes to shift down.
3
INSTRUMENT AND CONTROL FUNCTIONS
3-4
1
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1D0-F8199-E2.qxd 20/9/04 11:32 Página 18
EAU15950
EWA10270
s s
WARNING
Become thoroughly familiar
with all operating controls and
their functions before riding.
Consult a Yamaha dealer
regarding any control or func-
tion that you do not thoroughly
understand.
Never start the engine or ope-
rate it in a closed area for any
length of time. Exhaust fumes
are poisonous, and inhaling
them can cause loss of cons-
ciousness and death within a
short time. Always make sure
that there is adequate ventila-
tion.
Before starting out, make sure
that the sidestand is up. If the
sidestand is not raised comple-
tely, it could contact the
ground and distract the opera-
tor, resulting in a possible loss
of control.
EAU16060
Starting a cold engine
In order for the ignition circuit cut-off
system to enable starting, one of the
following conditions must be met:
The transmission is in the neutral
position.
The transmission is in gear with
the clutch lever pulled and the
sidestand up.
EWA10290
s s
WARNING
Before starting the engine,
check the function of the igni-
tion circuit cut-off system
according to the procedure
described on page 3-11.
Never ride with the sidestand
down.
1. Turn the fuel cock lever to “ON”.
2. Turn the key to “ON” and make
sure that the engine stop switch
is set to “f”.
3. Shift the transmission into the
neutral position.
NOTE:
When the transmission is in the neu-
tral position, the neutral indicator light
should be on, otherwise have a
Yamaha dealer check the electrical
circuit.
4. Turn the starter (choke) on and
completely close the throttle.
(See page 3-8.)
5. Start the engine by pushing the
start switch.
NOTE:
If the engine fails to start, release the
start switch, wait a few seconds, and
then try again. Each starting attempt
should be as short as possible to pre-
serve the battery. Do not crank the
engine more than 10 seconds on any
one attempt.
6. After starting the engine, move
the starter (choke) back halfway.
ECA11040
CAUTION
For maximum engine life, never
accelerate hard when the engine is
cold!
5
OPERATION AND IMPORTANT RIDING POINTS
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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
8-1
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