
FOR YOUR SAFETY – PRE-OPERATION CHECKS
4-1
4
EAU15596
Inspect your vehicle each time you use it to make sure the vehicle is in safe operating condition. Always follow the inspection
and maintenance procedures and schedules described in the Owner’s Manual.
WARNING
EWA11151
Failure to inspect or maintain the vehicle properly increases the possibility of an accident or equipment damage.
Do not operate the vehicle if you find any problem. If a problem cannot be corrected by the procedures provided in
this manual, have the vehicle inspected by a Yamaha dealer.Before using this vehicle, check the following points:
ITEM CHECKS PAGE
FuelCheck fuel level in fuel tank.
Refuel if necessary.
Check fuel line for leakage.3-8
Engine oilCheck oil level in engine.
If necessary, add recommended oil to specified level.
Check vehicle for oil leakage.6-9
CoolantCheck coolant level in reservoir.
If necessary, add recommended coolant to specified level.
Check cooling system for leakage.6-12
Front brakeCheck operation.
If soft or spongy, have Yamaha dealer bleed hydraulic system.
Check brake pads for wear.
Replace if necessary.
Check fluid level in reservoir.
If necessary, add recommended brake fluid to specified level.
Check hydraulic system for leakage.6-20, 6-20
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-10
64. If the engine oil is below the mini-
mum level mark, add sufficient oil
of the recommended type to raise
it to the correct level.
5. Install the oil filler cap.
To change the engine oil (with or
without oil filter element replace-
ment)
1. Start the engine, warm it up for
several minutes, and then turn it
off.
2. Place an oil pan under the engine
to collect the used oil.
3. Remove the engine oil filler cap
and the drain bolt along with the O-
ring, compression spring, and en-
gine oil strainer, to drain the oil
from the crankcase. NOTICE:
When removing the engine oil
drain bolt, the O-ring, compres-
sion spring, and oil strainer will
fall out. Take care not to lose
these parts.
[ECA11001]
4. Clean the engine oil strainer with
solvent.TIPSkip steps 5–7 if the oil filter element is
not being replaced.5. Remove the oil filter element cover
by removing the bolts.6. Remove and replace the oil filter
element and O-ring.
7. Install the oil filter element cover by
installing the bolts, then tightening
them to the specified torque.1. Engine oil drain bolt
2. O-ring
3. Compression spring
4. Strainer
1. Bolt
2. Oil filter element cover
1. Oil filter element
2. O-ring
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-11
6
TIPMake sure that the O-ring is properly
seated.8. Install the engine oil strainer, com-
pression spring, O-ring and the en-
gine oil drain bolt, and then tighten
it to the specified torque. NOTICE:
Before installing the engine oil
drain bolt, do not forget to in-
stall the O-ring, compression
spring, and oil strainer in posi-
tion.
[ECA10421]
9. Refill with the specified amount of
the recommended engine oil, and
then install and tighten the oil filler
cap.
NOTICE
ECA11620
In order to prevent clutch slip-
page (since the engine oil also
lubricates the clutch), do not
mix any chemical additives. Do
not use oils with a diesel speci-
fication of “CD” or oils of a high-
er quality than specified. In
addition, do not use oils labeled
“ENERGY CONSERVING II” or
higher.
Make sure that no foreign mate-
rial enters the crankcase.
10. Start the engine, and then let it idle
for several minutes while checking
it for oil leakage. If oil is leaking, im-
mediately turn the engine off and
check for the cause.11. Turn the engine off, and then
check the oil level and correct it if
necessary.
Tightening torque:
Oil filter element cover bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Tightening torque:
Engine oil drain bolt:
32 Nm (3.2 m·kgf, 23 ft·lbf)
Recommended engine oil:
See page 8-1.
Oil quantity:
Without oil filter element replace-
ment:
0.95 L (1.00 US qt, 0.84 Imp.qt)
With oil filter element replacement:
1.00 L (1.06 US qt, 0.88 Imp.qt)
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-21
6 Before riding, check that the brake fluid
is above the minimum level mark and
replenish if necessary. A low brake fluid
level may indicate worn brake pads
and/or brake system leakage. If the
brake fluid level is low, be sure to check
the brake pads for wear and the brake
system for leakage.
Observe these precautions:
When checking the fluid level,
make sure that the top of the brake
fluid reservoir is level.
Use only the recommended quality
brake fluid, otherwise the rubber
seals may deteriorate, causing
leakage and poor braking perfor-
mance.
Refill with the same type of brake
fluid. Mixing fluids may result in a
harmful chemical reaction and
lead to poor braking performance.
Be careful that water does not en-
ter the brake fluid reservoir when
refilling. Water will significantly
lower the boiling point of the fluid
and may result in vapor lock.
Brake fluid may deteriorate paint-
ed surfaces or plastic parts. Al-
ways clean up spilled fluid
immediately.
As the brake pads wear, it is nor-
mal for the brake fluid level to grad-
ually go down. However, if the
brake fluid level goes down sud-
denly, have a Yamaha dealer
check the cause.
EAUM1360
Changing the brake fluid Have a Yamaha dealer change the
brake fluid at the intervals specified in
the periodic maintenance and lubrica-
tion chart. In addition, have the brake
hose replaced every four years or
whenever it is damaged or leaking.
Recommended brake fluid:
DOT 4
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-24
6
EAU23101
Checking and lubricating the
cables The operation of all control cables and
the condition of the cables should be
checked before each ride, and the ca-
bles and cable ends should be lubricat-
ed if necessary. If a cable is damaged
or does not move smoothly, have a
Yamaha dealer check or replace it.
WARNING! Damage to the outer
sheath may interfere with proper ca-
ble operation and will cause the in-
ner cable to rust. Replace a
damaged cable as soon as possible
to prevent unsafe conditions.
[EWA10721]EAU23112
Checking and lubricating the
throttle grip and cable The operation of the throttle grip should
be checked before each ride. In addi-
tion, the cable should be lubricated by a
Yamaha dealer at the intervals speci-
fied in the periodic maintenance chart.
EAU23142
Checking and lubricating the
brake and clutch levers Brake lever
Clutch lever
The operation of the brake and clutch
levers should be checked before each
ride, and the lever pivots should be lu-
bricated if necessary.
Recommended lubricant:
Engine oil
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-26
6
EAUM2700
Lubricating the swingarm piv-
ots The swingarm pivots must be lubricat-
ed at the intervals specified in the peri-
odic maintenance and lubrication chart.
EAU23272
Checking the front fork The condition and operation of the front
fork must be checked as follows at the
intervals specified in the periodic main-
tenance and lubrication chart.
To check the condition
Check the inner tubes for scratches,
damage and excessive oil leakage.
To check the operation
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion. WARNING! To avoid injury,
securely support the vehicle so
there is no danger of it falling
over.
[EWA10751]
2. While applying the front brake,
push down hard on the handlebars
several times to check if the front
fork compresses and rebounds
smoothly.
NOTICE
ECA10590
If any damage is found or the front
fork does not operate smoothly,
have a Yamaha dealer check or re-
pair it.
Recommended lubricant:
Molybdenum disulfide grease
U22BE1E0.book Page 26 Wednesday, September 16, 2009 1:46 PM

SPECIFICATIONS
8-1
8
Dimensions:Overall length:
WR125R 2125 mm (83.7 in)
WR125X 2090 mm (82.3 in)
Overall width:
835 mm (32.9 in)
Overall height:
WR125R 1285 mm (50.6 in)
WR125X 1260 mm (49.6 in)
Seat height:
WR125R 930 mm (36.6 in)
WR125X 920 mm (36.2 in)
Wheelbase:
1430 mm (56.3 in)
Ground clearance:
WR125R 265 mm (10.43 in)
WR125X 255 mm (10.04 in)
Minimum turning radius:
2200 mm (86.6 in)Weight:With oil and fuel:
WR125R 133 kg (293 lb)
WR125X 137 kg (302 lb)Engine:Engine type:
Liquid cooled 4-stroke, SOHC
Cylinder arrangement:
Forward-inclined single cylinder
Displacement:
124 cm³
Bore × stroke:
52.0 × 58.6 mm (2.05 × 2.31 in)
Compression ratio:
11.20 :1Starting system:
Electric starter
Lubrication system:
Wet sump
Engine oil:Type:
SAE 10W-30, SAE 10W-40, SAE 15W-40,
SAE 20W-40 or SAE 20W-50
Recommended engine oil grade:
API service SG type or higher, JASO
standard MA
Engine oil quantity:
Without oil filter element replacement:
0.95 L (1.00 US qt, 0.84 Imp.qt)
With oil filter element replacement:
1.00 L (1.06 US qt, 0.88 Imp.qt)Cooling system:Coolant reservoir capacity (up to the
maximum level mark):
0.25 L (0.26 US qt, 0.22 Imp.qt)
Radiator capacity (including all routes):
1.10 L (1.16 US qt, 0.97 Imp.qt)
Air filter:Air filter element:
Dry elementFuel:Recommended fuel:
Premium unleaded gasoline only
Fuel tank capacity:
8.5 L (2.25 US gal, 1.87 Imp.gal)
Fuel reserve amount:
1.6 L (0.42 US gal, 0.35 Imp.gal)Fuel injection:Throttle body:
ID mark:
5D71 00Spark plug (s):Manufacturer/model:
NGK/CR8E
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)Clutch:Clutch type:
Wet, multiple-discTransmission:Primary reduction system:
Helical gear
Primary reduction ratio:
73/24 (3.042)
Secondary reduction system:
Chain drive
Secondary reduction ratio:
53/14 (3.786)
Transmission type:
Constant mesh 6-speed
-20 -10 0
10 20 30
40
50 ˚C
SAE 10W-30
SAE 15W-40SAE 20W-40SAE 20W-50
SAE 10W-40SAE 10W-50
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SPECIFICATIONS
8-2
8
Operation:
Left foot operation
Gear ratio:
1st:
34/12 (2.833)
2nd:
30/16 (1.875)
3rd:
30/22 (1.364)
4th:
24/21 (1.143)
5th:
22/23 (0.957)
6th:
21/25 (0.840)Chassis:Frame type:
Double cradle
Caster angle:
WR125R 27.00 °
WR125X 25.50 °
Trail:
WR125R 107.0 mm (4.21 in)
WR125X 78.5 mm (3.09 in)Front tire:Type:
With tube
Size:
WR125R 80/90-21M/C 48P
WR125X 110/70-17M/C 54H
Manufacturer/model:
WR125R PIRELLI / MT90 SCORPION
WR125X PIRELLI / SPORT DEMONManufacturer/model:
WR125R MICHELIN / SIRAC
Rear tire:Type:
With tube
Size:
WR125R 110/80-18 M/C 58P
WR125X 140/70-17 M/C 66H
Manufacturer/model:
WR125R PIRELLI / MT90 SCORPION
WR125X PIRELLI / SPORT DEMON
Manufacturer/model:
WR125R MICHELIN / SIRACLoading:Maximum load:
185 kg (408 lb)
(Total weight of rider, passenger, cargo and
accessories)Tire air pressure (measured on cold
tires):Loading condition:
0–90 kg (0–198 lb)
Front:
180 kPa (1.80 kgf/cm², 26 psi)
Rear:
200 kPa (2.00 kgf/cm², 29 psi)
Loading condition:
90–185 kg (198–408 lb)
Front:
200 kPa (2.00 kgf/cm², 29 psi)
Rear:
225 kPa (2.25 kgf/cm², 33 psi)
Front wheel:Wheel type:
Spoke wheel
Rim size:
WR125R 21x1.6
WR125X 17x3Rear wheel:Wheel type:
Spoke wheel
Rim size:
WR125R 18 x 2.15
WR125X 17 x MT3.5Front brake:Type:
Single disc brake
Operation:
Right hand operation
Recommended fluid:
DOT 4Rear brake:Type:
Single disc brake
Operation:
Right foot operation
Recommended fluid:
DOT 4Front suspension:Type:
Telescopic fork
Spring/shock absorber type:
Coil spring/oil damper
Wheel travel:
WR125R 240.0 mm (9.45 in)
WR125X 210.0 mm (8.27 in)
U22BE1E0.book Page 2 Wednesday, September 16, 2009 1:46 PM