Loading and accessories
Adding accessories or cargo to your
motorcycle can adversely affect sta-
bility and handling if the weight distri-
bution of the motorcycle is changed.
To avoid the possibility of an acci-
dent, use extreme caution when
adding cargo or accessories to your
motorcycle. Use extra care when
riding a motorcycle that has added
cargo or accessories. Here are some
general guidelines to follow if loading
cargo or adding accessories to your
motorcycle:
Loading
The total weight of the operator, pas-
senger, accessories and cargo must
not exceed the maximum load limit of
178 kg (392 lb) DT125R, 180 kg (396
lb) DT125X. When loading within this
weight limit, keep the following in
mind:
Cargo and accessory weight
should be kept as low and close
to the motorcycle as possible.
Make sure to distribute the
weight as evenly as possible on
both sides of the motorcycle to
minimize imbalance or instability.
Shifting weights can create a
sudden imbalance. Make sure
that accessories and cargo are
securely attached to the
motorcycle before riding. Check
accessory mounts and cargo res-
traints frequently.
Never attach any large or heavy
items to the handlebar, front fork,
or front fender. These items,
including such cargo as sleeping
bags, duffel bags, or tents, can
create unstable handling or a
slow steering response.
Accessories
Genuine Yamaha accessories have
been specifically designed for use on
this motorcycle. Since Yamaha can-
not test all other accessories that may
be available, you must personally be
responsible for the proper selection,
installation and use of non-Yamaha
accessories. Use extreme caution
when selecting and installing any
accessories.
Keep the following guidelines in mind,
as well as those provided under “Loa-
ding” when mounting accessories.
Never install accessories or carry
cargo that would impair the per-
formance of your motorcycle.
Carefully inspect the accessory
before using it to make sure that
it does not in any way reduce
ground clearance or cornering
clearance, limit suspension tra-
vel, steering travel or control ope-
ration, or obscure lights or reflec-
tors.
• Accessories fitted to the hand-
lebar or the front fork area can
create instability due to impro-
per weight distribution or
aerodynamic changes. If
accessories are added to the
handlebar or front fork area,
they must be as lightweight as
possible and should be kept to
a minimum.
1
tSAFETY INFORMATION
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EAU11002
Indicator and warning lights
1. Turn signal indicator light “b”
2. Dimmer indicator light “j”
3. Neutral indicator light “N”
4. Oil level warning light “z”
EAU11030
Turn signal indicator lights “c” and
“d”
The corresponding indicator light flas-
hes when the turn signal switch is
pushed to the left or right.
EAU11070
Neutral indicator light “N”
This indicator light comes on when
the transmission is in the neutral posi-
tion.
EAU11080
High beam indicator light “j”
This indicator light comes on when
the high beam of the headlight is swit-
ched on.
EAU11180
Oil level warning light “z”
This warning light comes on when the
key is in the “ON” position or when
the oil level in the 2-stroke engine oil
tank is low during operation. If the
warning light comes on during opera-
tion, stop immediately and fill the oil
tank with Yamalube 2 or equivalent 2-
stroke engine oil of either JASO grade
“FC” or ISO grades “EG-C” or “EG-
D”. The warning light should go off
after the 2-stroke engine oil tank has
been refilled.
NOTE:
If the warning light does not come on
when the key is in the “ON” position
or does not go off after the 2-stroke
engine oil tank has been refilled, have
a Yamaha dealer check the electrical
circuit.
ECA10010
CAUTION
Do not operate the vehicle until you
know that the engine oil level is suf-
ficient.
EAU11430
Coolant temperature warning light
“y”
This warning light comes on when the
engine overheats. When this occurs,
stop the engine immediately and
allow the engine to cool.
ECA10020
CAUTION
Do not operate the engine if it is
overheated.
0km/h406080
100
120
130 20
y
00001
5
0008
bj
zN
3
INSTRUMENT AND CONTROL FUNCTIONS
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EAU15090
Shock absorberEWA10220
s s
WARNING
This shock absorber contains
highly pressurized nitrogen gas.
For proper handling, read and
understand the following informa-
tion before handling the shock
absorber. The manufacturer cannot
be held responsible for property
damage or personal injury that may
result from improper handling.
Do not tamper with or attempt
to open the gas cylinder.
Do not subject the shock
absorber to an open flame or
other high heat sources, other-
wise it may explode due to
excessive gas pressure.
Do not deform or damage the
gas cylinder in any way, as this
will result in poor damping per-
formance.
Always have a Yamaha dealer
service the shock absorber.
EAU15250
YEIS handling precautions
1. YEIS
Improper installation of or damage to
any part of the YEIS (Yamaha Energy
Induction System) will result in poor
performance. Therefore, handle the
YEIS air chamber and air chamber
hose with special care and immedia-
tely replace any cracked or damaged
parts.
ECA10140
CAUTION
Do not attempt to modify the YEIS
in any way.
EAU15260
YPVS
1. YPVS
This model is equipped with the YPVS
(Yamaha Power Valve System). This
system boosts engine performance
and efficiency by means of a variable
valve in the exhaust port. The YPVS
valve is constantly adjusted in accor-
dance with the engine speed by a
computer-controlled servomotor.
Since the YPVS is an important part
of the engine and requires very sop-
histicated adjustment, have a Yamaha
dealer, who has the necessary profes-
sional knowledge and experience,
make this adjustment.
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INSTRUMENT AND CONTROL FUNCTIONS
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ECA10150
CAUTION
The YPVS has been set and exten-
sively tested at the Yamaha factory.
Changing these settings without
sufficient technical knowledge may
result in poor performance of or
damage to the engine.
YPVS operation noises can be heard
in the following instances:
When the key is turned to “ON”
and the engine is started.
When the engine stalls with the
key in the “ON” position.
ECA10160
CAUTION
If the YPVS does not operate, have
a Yamaha dealer check it.
EAU15300
Sidestand
The sidestand is located on the left
side of the frame. Raise the sidestand
or lower it with your foot while holding
the motorcycle upright.
NOTE:
The built-in sidestand switch is part of
the ignition circuit cut-off system,
which cuts the ignition in certain
situations. (See further down for an
explanation of the ignition circuit cut-
off system.)
EWA10240
s s
WARNING
The vehicle must not be ridden with
the sidestand down, or if the sides-
tand cannot be properly moved up
(or does not stay up), otherwise the
sidestand could contact the ground
and distract the operator, resulting
in a possible loss of control. Yama-
ha’s ignition circuit cut-off system
has been designed to assist the
operator in fulfilling the responsibi-
lity of raising the sidestand before
starting off. Therefore, check this
system regularly as described
below and have a Yamaha dealer
repair it if it does not function pro-
perly.
EAU15311
Ignition circuit cut-off
system
The ignition circuit cut-off system
(comprising the sidestand switch,
clutch switch and neutral switch) has
the following functions.
It prevents starting when the
transmission is in gear and the
sidestand is up, but the clutch
lever is not pulled.
It prevents starting when the
transmission is in gear and the
clutch lever is pulled, but the
sidestand is still down.
It cuts the running engine when
the transmission is in gear and
the sidestand is moved down.
Periodically check the operation of
the ignition circuit cut-off system
according to the following procedure.
EWA10250
s s
WARNING
If a malfunction is noted, have a
Yamaha dealer check the system
before riding.
3
INSTRUMENT AND CONTROL FUNCTIONS
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EAU15591
The condition of a vehicle is the
owner’s responsibility. Vital compo-
nents can start to deteriorate quickly
and unexpectedly, even if the vehicle
remains unused (for example, as a
result of exposure to the elements).
Any damage, fluid leakage or loss of
tire air pressure could have serious
consequences. Therefore, it is very
important, in addition to a thorough
visual inspection, to check the follo-
wing points before each ride.
NOTE:
Pre-operation checks should be
made each time the vehicle is used.
Such an inspection can be accom-
plished in a very short time; and the
added safety it assures is more than
worth the time involved.
EWA11150
s s
WARNING
If any item in the Pre-operation
check list is not working properly,
have it inspected and repaired
before operating the vehicle.
4
PRE-OPERATION CHECKS
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7. When the engine is warm, turn
the starter (choke) off.
NOTE:
The engine is warm when it responds
normally to the throttle with the starter
(choke) turned off.
EAU16640
Starting a warm engine
Follow the same procedure as for
starting a cold engine with the excep-
tion that the starter (choke) is not
required when the engine is warm.
EAU16671
Shifting
Shifting gears lets you control the
amount of engine power available for
starting off, accelerating, climbing
hills, etc.
The gear positions are shown in the
illustration.
N. Neutral
1. Shift pedal
NOTE:
To shift the transmission into the neu-
tral position, press the shift pedal down
repeatedly until it reaches the end of its
travel, and then slightly raise it.
ECA10260
CAUTION
Even with the transmission in
the neutral position, do not
coast for long periods of time
with the engine off, and do not
tow the motorcycle for long
distances. The transmission is
properly lubricated only when
the engine is running. Inade-
quate lubrication may damage
the transmission.
Always use the clutch while
changing gears to avoid dama-
ging the engine, transmission,
and drive train, which are not
designed to withstand the
shock of forced shifting.
EAU16830
Engine break-in
There is never a more important
period in the life of your engine than
the period between 0 and 1000 km
(600 mi). For this reason, you should
read the following material carefully.
Since the engine is brand new, do not
put an excessive load on it for the first
1000 km (600 mi). The various parts in
the engine wear and polish themsel-
ves to the correct operating clearan-
ces. During this period, prolonged
full-throttle operation or any condition
that might result in engine overhea-
ting must be avoided.
EAU17150
0–150 km (0–90 mi)
Avoid prolonged operation above 1/3
throttle.
5
OPERATION AND IMPORTANT RIDING POINTS
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EAU21340
Adjusting the engine idling
speed
1. Idle adjusting bolt
The engine idling speed must be
checked and, if necessary, adjusted
as follows at the intervals specified in
the periodic maintenance and lubrica-
tion chart.
The engine should be warm before
making this adjustment.
NOTE:
The engine is warm when it
quickly responds to the throttle.
A diagnostic tachometer is nee-
ded to make this adjustment.
1. Attach the tachometer to the
spark plug lead.2. Check the engine idling speed
and, if necessary, adjust it to spe-
cification by turning the throttle
stop screw. To increase the engi-
ne idling speed, turn the screw in
direction (a). To decrease the
engine idling speed, turn the
screw in direction (b).
Engine idling speed:
1250-1450 r/min
NOTE:
If the specified idling speed cannot be
obtained as described above, have a
Yamaha dealer make the adjustment.
EAU21370
Adjusting the throttle cable
free play
(a) Free play
The throttle cable free play should
measure 3-5 mm (0,11-0,19 in) at the
throttle grip. Periodically check the
throttle cable free play and, if neces-
sary, adjust it as follows.
NOTE:
The engine idling speed must be
correctly adjusted before checking
and adjusting the throttle cable free
play.
1. Lock nut
2. Adjusting nut
1. Loosen the locknut.
2. To increase the throttle cable free
play, turn the adjusting nut in
direction (a). To decrease the
throttle cable free play, turn the
adjusting nut in direction (b).
3. Tighten the locknut.
6
PERIODIC MAINTENANCE AND MINOR REPAIR
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Tire inspection
1.Wear limit
2. Side wall
The tires must be checked before
each ride. If the center tread depth
reaches the specified limit, if the tire
has a nail or glass fragments in it, or if
the sidewall is cracked, have a Yama-
ha dealer replace the tire immediately.
Minimum tire tread depth (front and
rear):
1.6 mm (0.06 in)
NOTE:
The tire tread depth limits may differ
from country to country. Always
comply with the local regulations.
Tire information
This motorcycle is equipped with tube
tires.
EWA10460
s s
WARNING
The front and rear tires should
be of the same make and
design, otherwise the handling
characteristics of the vehicle
cannot be guaranteed.
After extensive tests, only the
tires listed below have been
approved for this model by
Yamaha Motor España, S.A.
DT125R
Front tire:
Size:
80/90-21 48P
Manufacturer/model:
MICHELIN / T63
Rear tire:
Size:
110/80-18 58P
Manufacturer/model:
MICHELIN / T63
DT125X
Front tire:
Size:
120/70-17 58H
Manufacturer/model:
Pirelli/Sport Demon
Rear tire:
Size:
140/70-17 66H
Manufacturer/model:
Pirelli/Sport Demon
6
PERIODIC MAINTENANCE AND MINOR REPAIR
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