Page 48 of 88

PERIODIC MAINTENANCE AND ADJUSTMENT
6-12
6
EAU20070
Coolant The coolant level should be checked
before each ride. In addition, the cool-
ant must be changed at the intervals
specified in the periodic maintenance
and lubrication chart.
EAUM2592
To check the coolant level
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion.TIP
The coolant level must be checked
on a cold engine since the level
varies with engine temperature.
Make sure that the vehicle is posi-
tioned straight up when checking
the coolant level. A slight tilt to theside can result in a false reading.
2. Check the coolant level in the cool-
ant reservoir.
TIPThe coolant should be between theminimum and maximum level marks.3. If the coolant is at or below the
minimum level mark, remove the
seat (See page 3-10.), and then
open the coolant reservoir cap.4. Add coolant or distilled water to
raise the coolant to the specified
level, close the coolant reservoir
cap, and then install the seat.
WARNING! Remove only the
coolant reservoir cap. Never at-
tempt to remove the radiator
cap when the engine is hot.
[EWA15161]
NOTICE: If coolant is not
available, use distilled water or
soft tap water instead. Do not
use hard water or salt water
since it is harmful to the engine.
If water has been used instead
of coolant, replace it with cool-
ant as soon as possible, other-
wise the cooling system will not
be protected against frost and
corrosion. If water has been
added to the coolant, have a
Yamaha dealer check the anti-
freeze content of the coolant as
soon as possible, otherwise the
effectiveness of the coolant will
be reduced.
[ECA10472]
1. Coolant reservoir
2. Maximum level mark
3. Minimum level mark
1. Coolant reservoir cap
Coolant reservoir capacity:
0.25 L (0.26 US qt, 0.22 Imp.qt)
U22BE0E0.book Page 12 Wednesday, December 17, 2008 11:00 AM
Page 79 of 88

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 133.0 kg (293 lb)
WR125X 137.0 kg (302 lb)Engine:Engine type:
Liquid cooled 4-stroke, SOHC
Cylinder arrangement:
Forward-inclined single cylinder
Displacement:
124.7 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:
Type/quantity:
SE AC28-2/1Spark 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
U22BE0E0.book Page 1 Wednesday, December 17, 2008 11:00 AM
Page 81 of 88
SPECIFICATIONS
8-3
8
Rear suspension:Type:
Swingarm (monocross)
Spring/shock absorber type:
WR125R Coil spring/gas-oil damper
WR125X Coil spring/oil damper
Wheel travel:
230.0 mm (9.06 in)Electrical system:Ignition system:
TCI (digital)
Charging system:
AC magnetoBattery:Model:
12N5.5-4A
Voltage, capacity:
12 V, 5.5 AhHeadlight:Bulb type:
Halogen bulbBulb voltage, wattage × quantity:Headlight:
12 V, 35 W/35 W × 1
Tail/brake light:
12 V, 21.0 W/5.0 W × 1
Front turn signal light:
12 V, 10.0 W × 2
Rear turn signal light:
12 V, 10.0 W × 2
Auxiliary light:
12 V, 5.0 W × 1
License plate light:
12 V, 5.0 W × 1Meter lighting:
LED
Neutral indicator light:
LED
High beam indicator light:
LED
Turn signal indicator light:
LED
Coolant temperature warning light:
LED
Engine trouble warning light:
LED
Fuses:Main fuse:
20.0 A
Headlight fuse:
15.0 A
Signaling system fuse:
7.5 A
Ignition fuse:
7.5 A
Radiator fan fuse:
5.0 A
U22BE0E0.book Page 3 Wednesday, December 17, 2008 11:00 AM