Yamaha Wr250r 2008 Manual

							 
ENGINE SPECIFICATIONS 
2-6 
Piston ring 
Top ring
Ring type Barrel
Dimensions (B  
× 
 T) 0.90  
×  
 2.75 mm (0.04   
×  
 0.11 in)
End gap (installed) 0.15 
–  
0.25 mm (0.0059  
–  
0.0098 in)
Limit 0.50 mm (0.0197 in)
Ring side clearance 0.030 
–  
0.065 mm (0.0012  
–  
0.0026 in)
Limit 0.115 mm (0.0045 in)
2nd ring
Ring type Taper
Dimensions (B  
× 
 T) 0.80  
×  
 2.75 mm (0.03   
×  
 0.11 in)
End gap (installed) 0.30 
–  
0.45 mm (0.0118  
–  
0.0177 in)
Limit 0.80 mm (0.0315 in)
Ring side clearance 0.020 
–  
0.055 mm (0.0008  
–  
0.0022 in)
Limit 0.115 mm (0.0045 in)
Oil ring
Dimensions (B  
× 
 T) 1.50  
× 
 2.25 mm (0.06  
×  
 0.09 in)
End gap (installed) 0.10 
– 
0.40 mm (0.0039 
–  
0.0157 in) 
Crankshaft 
Width A 61.95 
– 
62.00 mm (2.439 
–  
2.441 in)
Runout limit C 0.030 mm (0.0012 in)
Big end side clearance D 0.350 
– 
0.650 mm (0.0138 
–  
0.0256 in) 
Balancer 
Balancer drive method Gear 
Clutch 
Clutch type Wet, multiple-disc
Clutch release method Inner push, cam push
Clutch lever free play 10.0 
– 
15.0 mm (0.39 
– 
0.59 in)
T
B
B
T
B
T
CC
D
A 
						

							 
ENGINE SPECIFICATIONS 
2-7 
Friction plate thickness 2.90 
–  
3.10 mm (0.114  
–  
0.122 in)
Wear limit 2.80 mm (0.1102 in)
Plate quantity 7 pcs
Clutch plate thickness 1.50 
–  
1.70 mm (0.059  
–  
0.067 in)
Plate quantity 6 pcs
Warpage limit 0.10 mm (0.0039 in)
Clutch spring free length 41.20 mm (1.62 in)
Minimum length 39.14 mm (1.54 in)
Spring quantity 5 pcs
Push rod bending limit 0.100 mm (0.0039 in) 
Transmission 
Transmission type Constant mesh 6-speed
Primary reduction system Spur gear
Primary reduction ratio 78/25 (3.120)
Secondary reduction system Chain drive
Secondary reduction ratio WR250R 43/13 (3.307)
 WR250X 42/13 (3.231)
Operation Left foot operation
Gear ratio
1st 37/14 (2.642)
2nd 29/16 (1.813)
3rd 29/22 (1.318)
4th 26/25 (1.040)
5th 24/27 (0.888)
6th 22/28 (0.786) 
Shifting mechanism 
Shift mechanism type Shift drum and guide bar
Shift fork guide bar bending limit 0.050 mm (0.0020 in)
Shift fork thickness 4.85 mm (0.1909 in) 
Decompression device 
Device type Auto decomp 
Air filter 
Air filter element Wet element
Air filter oil grade Foam air-filter oil or engine oil 
Throttle body 
Type/quantity 38EIS/1
Manufacturer MIKUNI
ID mark WR250R 32C3 00 (CAL)
WR250R 3D71 10 (U49)
WR250X 32C3 00 (CAL)
WR250X 3D71 10 (U49) 
Fuel injection sensor 
Crankshaft position sensor 248 
–  
278   
Ω  
Intake air pressure sensor output voltage 3.75 
–  
4.25 V
Coolant temperature sensor resistance 2320 
–  
2590   
Ω  
@20   
°  
C (68  
°  
F)
310 
– 
326  
Ω  
@80   
°  
C (176   
°  
F) 
Idling condition 
Engine idling speed 1450 
– 
1650 r/min
Intake vacuum 28.3 kPa (8.4 inHg) (212 mmHg)
Water temperature 80  
° 
C (176  
° 
F) 
						

							 
ENGINE SPECIFICATIONS 
2-8 
Oil temperature 60.0  
°  
C (140.00   
°  
F)
Throttle cable free play 3.0 
–  
5.0 mm (0.12  
–  
0.20 in) 
						

							 
CHASSIS SPECIFICATIONS 
2-9 
EAS20300 
CHASSIS SPECIFICATIONS 
Chassis 
Frame type Semi double cradle
Caster angle WR250R 26.67  
°  
WR250X 25.33   
°  
Trail WR250R 111.0 mm (4.37 in)
WR250X 76.0 mm (2.99 in) 
Front wheel 
Wheel type Spoke wheel
Rim size WR250R 21x1.60
WR250X 17M/C x MT3.00
Rim material Aluminum
Wheel travel 270.0 mm (10.63 in)
Radial wheel runout limit 2.0 mm (0.08 in)
Lateral wheel runout limit 2.0 mm (0.08 in)
Wheel axle bending limit 0.50 mm (0.02 in) 
Rear wheel 
Wheel type Spoke wheel
Rim size WR250R 18x2.15
WR250X 17M/C x MT4.00
Rim material Aluminum
Wheel travel WR250R 270.0 mm (10.63 in)
WR250X 265.0 mm (10.43 in)
Radial wheel runout limit 2.0 mm (0.08 in)
Lateral wheel runout limit 2.0 mm (0.08 in)
Wheel axle bending limit 0.50 mm (0.02 in) 
Front tire 
Type With tube
Size WR250R 80/100-21M/C 51P
WR250X 110/70R17M/C 54H
Manufacturer/model WR250R BRIDGESTONE/TW-301 F
WR250X BRIDGESTONE/BT090F RADIAL G 
Rear tire 
Type With tube
Size WR250R 120/80-18M/C 62P
WR250X 140/70R17M/C 66H
Manufacturer/model WR250R BRIDGESTONE/TW-302 F
WR250X BRIDGESTONE/BT090R RADIAL G 
Tire air pressure (measured on cold tires) 
Loading condition 0–90 kg (0–198 lb)
Front WR250R 125 kPa (18 psi) (1.25 kgf/cm 
2
 
)
WR250X 200 kPa (29 psi) (2.00 kgf/cm 
2
 
)
Rear WR250R 175 kPa (25 psi) (1.75 kgf/cm 
2
 
)
WR250X 200 kPa (29 psi) (2.00 kgf/cm 
2
 
)
Loading condition 90 
–  
185 kg (198  
–  
408 lb)
Front WR250R 150 kPa (22 psi) (1.50 kgf/cm 
2
 
)
WR250X 200 kPa (29 psi) (2.00 kgf/cm 
2
 
)
Rear WR250R 200 kPa (29 psi) (2.00 kgf/cm 
2
 
)
WR250X 225 kPa (33 psi) (2.25 kgf/cm 
2
 
) 
						

							 
CHASSIS SPECIFICATIONS 
2-10 
Front brake 
Type Single disc brake
Operation Right hand operation
Front brake lever free play 5.0 
–  
8.0 mm (0.20  
–  
0.31 in)
Front disc brake
Disc outside diameter  
× 
 thickness WR250R 250.0  
×  
 3.5 mm (9.84   
×  
 0.14 in)
WR250X 298.0   
×  
 4.0 mm (11.73   
×  
 0.16 in)
Brake disc thickness limit WR250R 3.0 mm (0.12 in)
WR250X 3.5 mm (0.14 in)
Brake disc deflection limit 0.15 mm (0.0059 in)
Brake pad lining thickness (inner) WR250R 4.8 mm (0.19 in)
WR250X 4.0 mm (0.16 in)
Limit 1.0 mm (0.04 in)
Brake pad lining thickness (outer) WR250R 4.8 mm (0.19 in)
WR250X 4.0 mm (0.16 in)
Limit 1.0 mm (0.04 in)
Master cylinder inside diameter WR250R 11.00 mm (0.43 in)
WR250X 12.70 mm (0.50 in)
Caliper cylinder inside diameter 27.00 mm  
×  
 2 (1.06 in   
×  
 2)
Recommended fluid DOT 4 
Rear brake 
Type Single disc brake
Operation Right foot operation
Brake pedal position 11.5 mm (0.45 in)
Rear disc brake
Disc outside diameter  
× 
 thickness 230.0  
×  
 4.5 mm (9.06   
×  
 0.18 in)
Brake disc thickness limit 4.0 mm (0.16 in)
Brake disc deflection limit 0.15 mm (0.0059 in)
Brake pad lining thickness (inner) 6.4 mm (0.25 in)
Limit 1.0 mm (0.04 in)
Brake pad lining thickness (outer) 6.4 mm (0.25 in)
Limit 1.0 mm (0.04 in)
Master cylinder inside diameter 11.0 mm (0.43 in)
Caliper cylinder inside diameter 25.40 mm  
×  
 1 (1.00 in   
×  
 1)
Recommended fluid DOT 4 
Steering 
Steering bearing type Taper roller bearing
Center to lock angle (left) 44.0  
° 
Center to lock angle (right) 44.0  
° 
Front suspension 
Type Telescopic fork
Spring/shock absorber type Coil spring/oil damper
Front fork travel 270.0 mm (10.63 in)
Fork spring free length 450.0 mm (17.72 in)
Limit 441.0 mm (17.36 in)
Installed length 439.2 mm (17.29 in)
Spring rate K1 4.60 N/mm (26.27 lb/in) (0.47 kgf/mm)
Spring stroke K1 0.0 
– 
270.0 mm (0.00 
–  
10.63 in)
Inner tube outer diameter 46.0 mm (1.81 in)
Inner tube bending limit 0.2 mm (0.01 in)
Optional spring available No 
						

							 
CHASSIS SPECIFICATIONS 
2-11 
Recommended oil Suspension oil 01
Quantity 613.0 cm 
3
 
 (20.73 US oz) (21.62 Imp.oz)
Level 105.0 mm (4.13 in)
Rebound damping adjusting positions
Minimum 12
Standard 10
Maximum 1
Compression damping adjusting positions
Minimum 19
Standard 10
Maximum 1 
Rear suspension 
Type Swingarm (link suspension)
Spring/shock absorber type Coil spring/gas-oil damper
Rear shock absorber assembly travel 95.0 mm (3.74 in)
Spring free length 220.0 mm (8.66 in)
Installed length 211.5 mm (8.33 in)
Spring rate K1 80.00 N/mm (456.80 lb/in) (8.16 kgf/mm)
Spring stroke K1 0.0 
–  
95.0 mm (0.00  
–  
3.74 in)
Optional spring available No
Enclosed gas/air pressure (STD) 1200 kPa (170.7 psi) (12.0 kgf/cm 
2
 
)
Spring preload adjusting positions
Minimum 216.0 mm (8.50 in)
Standard 211.5 mm (8.33 in)
Maximum 206.0 mm (8.11 in)
Rebound damping  adjusting positions
Minimum 25
Standard WR250R 12
WR250X 13
Maximum 3
Compression damping adjusting positions
Minimum 12
Standard WR250R 10
WR250X 7
Maximum 1 
Swingarm 
Swingarm end free play limit (radial) 1.0 mm (0.04 in)
Swingarm end free play limit (axial) 1.0 mm (0.04 in) 
Drive chain 
Type/manufacturer 520V/DAIDO
Link quantity 108
Drive chain slack WR250R 38.0 
–  
48.0 mm (1.50  
–  
1.89 in)
WR250X 40.0  
–  
50.0 mm (1.57  
–  
1.97 in)
15-link length limit 239.3 mm (9.42 in) 
						

							 
ELECTRICAL SPECIFICATIONS 
2-12 
EAS20310 
ELECTRICAL SPECIFICATIONS 
Voltage 
System voltage 12 V 
Ignition system 
Ignition system TCI (digital)
Advancer type Digital
Ignition timing (B.T.D.C.) 10.0  
° 
Engine control unit 
Model/manufacturer TBDF88/DENSO 
Ignition coil 
Model/manufacturer F6T558/MITSUBISHI
Primary coil resistance 1.19 
–  
1.61   
Ω  
Secondary coil resistance 8.50 
–  
11.50 k  
Ω 
AC magneto 
Model/manufacturer F3D7/YAMAHA
Standard output 14.0 V, 350 W@5000 r/min
Stator coil resistance 0.168 
–  
0.252   
Ω  
 (W-W)
Rectifier/regulator
Regulator type Semi conductor-short circuit
Model/manufacturer SH678-11/SHINDENGEN
No load regulated voltage 14.1 
–  
14.9 V
Rectifier capacity (DC) 35.0 A
Withstand voltage 200.0 V 
Battery 
Model YTZ7S
Voltage, capacity 12 V, 6.0 Ah
Specific gravity 1.310
Manufacturer GS YUASA
Ten hour rate amperage 0.60 A 
Headlight 
Bulb type Halogen bulb 
Bulb voltage, wattage  
× 
 quantity 
Headlight 12 V, 60 W/55.0 W
Tail/brake light LED
Front turn signal/position light 12 V, 21.0 W/5.0 W  
×  
 2
Rear turn signal light 12 V, 21.0 W  
×  
 2
License plate light 12 V, 5.0 W 
Indicator light 
Neutral indicator light LED
Turn signal indicator light LED
High beam indicator light LED
Fuel level warning light LED
Coolant temperature warning light LED
Engine trouble warning light LED 
Electric starting system 
System type Constant mesh 
						

							 
ELECTRICAL SPECIFICATIONS 
2-13 
Starter motor 
Model/manufacturer SM-14/MITSUBA
Power output 0.50 kW
Armature coil resistance 0.0040 
–  
0.0050   
Ω  
Brush overall length 10.0 mm (0.39 in)
Limit 3.50 mm (0.14 in)
Brush spring force 7.16 
–  
9.52 N (25.77  
–  
34.27 oz) (730  
–  
971 gf)
Commutator diameter 28.0 mm (1.10 in)
Limit 27.0 mm (1.06 in)
Mica undercut (depth) 0.70 mm (0.03 in) 
Starter relay 
Model/manufacturer A3943-072/JIDECO
Amperage 180.0 A
Coil resistance 4.18 
–  
4.62   
Ω 
Horn 
Horn type Plane
Quantity 1 pcs
Model/manufacturer HF-12/NIKKO
Maximum amperage 3.0 A
Coil resistance 1.01 
–  
1.11   
Ω  
Performance 108 
–  
116 dB/2m 
Turn signal relay 
Relay type Full transistor
Model/manufacturer FE246BH/DENSO
Built-in, self-canceling device No
Turn signal blinking frequency 75 
– 
95 cycles/min 
Starting circuit cut-off relay 
Model/manufacturer G8R-30Y-V4/OMRON
Coil resistance 162.0 
– 
198.0  
Ω 
Headlight relay 
Model/manufacturer ACM33211 M04/MATSUSHITA
Coil resistance 86.40 
– 
105.60  
Ω 
Sidestand relay 
Model/manufacturer G8R-30Y-V4/OMRON 
Fuel pump relay 
Model/manufacturer G8R-30Y-V4/OMRON
Coil resistance 162 
– 
198  
Ω 
Fan motor relay 
Model/manufacturer ACM33211 M04/MATSUSHITA 
Fuses 
Main fuse 30.0 A
Headlight fuse 15.0 A
Signaling system fuse 10.0 A
Ignition fuse 7.5 A
Radiator fan fuse 7.5 A
Fuel injection system fuse 7.5 A
Backup fuse 7.5 A
Spare fuse 30.0 A 
						

							 
ELECTRICAL SPECIFICATIONS 
2-14 
Spare fuse 15.0 A
Spare fuse 10.0 A
Spare fuse 7.5 A 
						

							 
TIGHTENING TORQUES 
2-15 
EAS20320 
TIGHTENING TORQUES 
EAS20330 
GENERAL TIGHTENING TORQUE 
SPECIFICATIONS 
This chart specifies tightening torques for stan-
dard fasteners with a standard ISO thread pitch.
Tightening torque specifications for special com-
ponents or assemblies are provided for each
chapter of this manual. To avoid warpage, tight-
en multi-fastener assemblies in a crisscross pat-
tern and progressive stages until the specified
tightening torque is reached. Unless otherwise
specified, tightening torque specifications re-
quire clean, dry threads. Components should be
at room temperature. 
EAS20340 
ENGINE TIGHTENING TORQUES 
A. Distance between flats
B.  Outside thread diameter  
A (nut) B (bolt)General tightening torques
Nm m•kg ft•lb  
10 mm 6 mm 6 0.6 4.3
12 mm 8 mm 15 1.5 11
14 mm 10 mm 30 3.0 22
17 mm 12 mm 55 5.5 40
19 mm 14 mm 85 8.5 61
22 mm 16 mm 130 13.0 94 
ItemThread 
sizeQ’ty Tightening torque Remarks  
Camshaft cap bolt M6 8 10 Nm (1.0 m•kg, 7.2 ft•lb)
Cylinder head straight screw plug M12 1 28 Nm (2.8 m•kg, 20 ft•lb)
Cylinder head stud bolt (exhaust 
pipe bolt)M8 2 15 Nm (1.5 m•kg, 11 ft•lb)
Spark plug M10 1 13 Nm (1.3 m•kg, 9.4 ft•lb)
Cylinder head bolt M10 4 40 Nm (4.0 m•kg, 29 ft•lb)
Cylinder head cover bolt M6 2 12 Nm (1.2 m•kg, 8.7 ft•lb)
Cylinder head bolt M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Oil check bolt M8 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Cylinder head cover bolt (small 
head)M6 5 10 Nm (1.0 m•kg, 7.2 ft•lb)
Balancer weight screw M6 3 10 Nm (1.0 m•kg, 7.2 ft•lb)
Balancer gear nut M14 1 50 Nm (5.0 m•kg, 36 ft•lb)lock 
washer 
use
Rotor nut M12 1 65 Nm (6.5 m•kg, 47 ft•lb)
Cam sprocket bolt M7 4 24 Nm (2.4 m•kg, 17 ft•lb)
Timming chain tensioner bolt M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
LT
LT
LT