2008 YAMAHA WR 250F Owners Manual

2-6
MAINTENANCE SPECIFICATIONS
Compressed force (installed) (EX)126–144 N at 29.30 mm (12.85–14.68 kg
at 29.30 mm, 28.32–32.37 lb at 1.15 in) ----
Tilt limit* (IN) ----2.5°/1.6 mm
(2.5°/0.063 in)
Tilt limit* (EX) ----2.5°/1.6 mm
(2.5°/0.063 in)
Direction of winding (top view) (IN) Clockwise----
Direction of winding (top view) (EX) Clockwise----
Piston: Piston to cylinder clearance 0.030–0.055 mm (0.0012–0.0022 in) 0.1 mm (0.004
in)
Piston size "D" 76.955–76.970 mm (3.0297–3.0303 in) ----
Measuring point "H " 8 mm (0.31 in) ----
Piston off-set 0.5 mm (0.020 in)/IN-side ----
Piston pin bore inside diameter 16.002–16.013 mm (0.6300–0.6304 in) 16.043 mm
(0.6316 in)
Piston pin outside diameter 15.991–16.000 mm (0.6296–0.6299 in) 15.971 mm
(0.6288 in)
Piston rings: Top ring:
Type Barrel----
Dimensions (B × T) 0.90 × 2.75 mm (0.04 × 0.11 in)----
End gap (installed) 0.15–0.25 mm (0.006–0.010 in) 0.50 mm (0.020
in)
Side clearance (installed) 0.030–0.065 mm (0.0012–0.0026 in) 0.12 mm (0.005
in)
2nd ring:
Type Taper----
Dimensions (B × T) 0.80 × 2.75 mm (0.03 × 0.11 in)----
End gap (installed) 0.30–0.45 mm (0.012–0.018 in) 0.80 mm (0.031
in)
Item
StandardLimit

2-7
MAINTENANCE SPECIFICATIONS
Side clearance0.020–0.055 mm (0.0008–0.0022 in) 0.12 mm (0.005
in)
Oil ring:
Dimensions (B × T) 1.50 × 2.25 mm (0.06 × 0.09 in)----
End gap (installed) 0.10–0.40 mm (0.004–0.016 in)----
Crankshaft: Crank width "A" 55.95–56.00 mm (2.203–2.205 in) ----
Runout limit "C" 0.03 mm (0.0012 in)0.05 mm (0.002
in)
Big end side clearance "D" 0.15–0.45 mm (0.0059–0.0177 in) 0.50 mm (0.02
in)
Small end free play "F" 0.4–1.0 mm (0.02–0.04 in)2.0 mm (0.08
in)
Clutch: Friction plate thickness 2.9–3.1 mm (0.114–0.122 in)2.7 mm (0.106
in)
Quantity 9----
Clutch plate thickness 1.1–1.3 mm (0.043–0.051 in)----
Quantity 8----
Warp limit ----0.1 mm (0.004
in)
Clutch spring free length 37.0 mm (1.46 in)36.0 mm (1.42
in)
Quantity 5----
Clutch housing thrust clearance 0.10–0.35 mm (0.0039–0.0138 in) ----
Clutch housing radial clearance 0.010–0.044 mm (0.0004–0.0017 in) ----
Clutch release method Inner push, cam push----
Shifter: Shifter type Cam drum and guide bar----
Guide bar bending limi t ---- 0.05 mm (0.002
in)
Kickstarter: Type Kick and ratchet type----
Item
StandardLimit

2-8
MAINTENANCE SPECIFICATIONS
Carburetor:USA, CDN, ZA,
AUS, NZ EUROPE
Type/manufacturer FCR-MX37/KEIHIN← ----
I. D. mark 5UME E05UML L0----
Main jet (M.J) #170#160----
Main air jet (M.A.J) #115← ----
Jet needle (J.N) NJRUNNGU----
Cutaway (C.A) 1.5←----
Pilot jet (P.J) #42#45 ----
Pilot air jet (P.A.J) #70← ----
Pilot outlet (P.O) ø0.9←----
Bypass (B.P) ø1.0←----
Valve seat size (V.S) ø3.8←----
Starter jet (G.S) #68← ----
Leak jet (Acc.P) #70← ----
Float height (F.H) 8 mm (0.31 in)← ----
Engine idle speed 1,750–1,950 r/min← ----
Intake vacuum 31.3–36.7 kPa
(235–275 mmHg,
9.25–10.83 inHg) ←
----
Hot starter lever free play 3–6 mm (0.12–0.24
in) ←
----
Lubrication system: Oil filter type Paper type----
Oil pump type Trochoid type----
Tip clearance 0.12 mm or less (0.0047 in or less) 0.20 mm (0.008
in)
Side clearance 0.09–0.17 mm (0.0035–0.0067 in) 0.24 mm (0.009
in)
Housing and rotor clearance 0.03–0.10 mm (0.0012–0.0039 in) 0.17 mm
(0.0067 in)
Cooling: Radiator core sizeWidth 120.2 mm (4.73 in)----
Height 240 mm (9.45 in)----
Thickness 22 mm (0.87 in)----
Radiator cap opening pressure 110 kPa (1.1 kg/cm
2, 15.6 psi)----
Radiator capacity (total) 0.54 L (0.48 Imp qt, 0.57 US qt)----
Water pump Type Single-suction centrifugal pump----
Item
StandardLimit

2-9
MAINTENANCE SPECIFICATIONS
CHASSISItem Standard Limit
Steering system: Steering bearing type Taper roller bearing ----
Front suspension: Front fork travel 300 mm (11.8 in) ----
Fork spring free length 460 mm (18.1 in) 455 mm (17.9 in)
Spring rate, STD K = 4.4 N/mm (0.449 kg/mm, 25.1 lb/in)----
Optional spring/spacer Yes----
Oil capacity 648 cm
3 (22.8 lmp oz, 21.9 US oz)----
Oil level 132 mm (5.20 in)----
(From top of outer tube with inner
tube and damper rod fully compressed without
spring.) 95–150 mm (3.74–5.91 in)
----
Oil grade Suspension oil "S1"----
Inner tube outer diamet er 48 mm (1.89 in) ----
Front fork top end 5 mm (0.20 in)----
Rear suspension: USA, CDN AUS, NZ, ZA EUROPE
Shock absorber travel 130 mm (5.12
in) ←←----
Spring free length 260 mm (10.24
in) ←←----
Fitting length 249 mm (9.80
in) 245.0 mm (9.65
in)248.5 mm (9.78
in)----
238.5–258.5
mm (9.39–
10.18 in) ←←----
Spring rate, STD K = 52.0 N/mm
(5.30 kg/mm,
296.8 lb/in) ←←----
Optional spring Yes←←----
Enclosed gas pressure 1,000 kPa (10
kg/cm
2, 142
psi) ←←----
Swingarm: Swingarm free play limitEnd ---- 1.0 mm (0.04 in)
Wheel: USA, CDN, ZA AUS, NZ, EUROPE
Front wheel type Spoke wheel←----
Rear wheel type Spoke wheel←----
Front rim size/material 21 × 1.60/Aluminum←----
Rear rim size/mater ial 18 × 1.85/Aluminum 18 × 2.15/Aluminum ----
Rim runout limit: Radial --------2.0 mm (0.08
in)
Lateral --------2.0 mm (0.08
in)

2-10
MAINTENANCE SPECIFICATIONS
ELECTRICALDrive chain:
Type/manufacturer DID520VM/DAIDO----
Number of links 113 links + joint----
Chain slack 48–58 mm (1.9–2.3 in)----
Chain length (15 links) ----239.3 mm
(9.42 in)
Front disc brake: Disc outside dia.×Thickness 250 × 3.0 mm (9.84 × 0.12 in)250 × 2.5 mm
(9.84 × 0.10 in)
Pad thickness 4.4 mm (0.17 in)1.0 mm (0.04
in)
Master cylinder inside dia. 11.0 mm (0.433 in)----
Caliper cylinder inside dia. 27.0 mm (1.063 in) × 2----
Brake fluid type DOT #4----
Rear disc brake: Disc outside dia.×Thickness 245 × 4.0 mm (9.65 × 0.16 in)245 × 3.5 mm
(9.65 × 0.14 in)
Deflection limit ----0.15 mm
(0.006 in)
Pad thickness 6.4 mm (0.25 in)1.0 mm (0.04
in)
Master cylinder inside dia. 11.0 mm (0.433 in)----
Caliper cylinder inside dia. 25.4 mm (1.000 in) × 1----
Brake fluid type DOT #4----
Brake lever and brake pedal: Brake lever position 95 mm (3.74 in)----
Brake pedal height (vertical height above footrest
top) 10 mm (0.39 in)
----
Clutch lever free play (lever end) 8–13 mm (0.31–0.51 in)----
Throttle grip free play 3–5 mm (0.12–0.20 in)----
Item
StandardLimit
Item StandardLimit
Ignition system: Advancer type Electrical----
CDI: USA, CDN, ZA,
AUS, NZ EUROPE
Pickup coil resistance (color) 248–372 Ωat 20 °C
(68 °F) (White–Red) ←
----
CDI unit-model/manufacturer 5UM-F0/YAMAHA 5UM-L0/YAMAHA ----
Ignition coil: Model/manufacturer 5UL-10/DENSO----
Minimum spark gap 6 mm (0.24 in)----
Primary coil resistance 0.08–0.10 Ωat 20 °C (68 °F) ----
Secondary coil resistance 4.6–6.8 kΩat 20 °C (68 °F) ----
Charging system: System type AC magneto----
Model (stator)/manufacturer 5UM 30/YAMAHA----

2-11
TIGHTENING TORQUES
TIGHTENING TORQUES
ENGINE
△- marked portion shall be checked for torque ti ghtening after break-in or before each race.
Normal output 14 V/120 W at 5,000 r/min----
Charging coil resistance (color) 0.288–0.432 Ω at 20 °C (68 °F) (White–
Ground) ----
Lighting coil resistance (color) 0.224–0.336 Ω at 20 °C (68 °F) (Yellow–
Ground) ----
Rectifier/regulator: Regulator type Semiconductor short circuit----
Model/manufacture SH770AA/SHINDENGEN----
Regulated voltage (AC) 12.5–13.5 V----
Regulated voltage (DC) 14.0–15.0 V----
Rectifier capacity (AC) 12 A----
Rectifier capacity (DC) 8 A----
Electric starting system: Type Constant mesh----
Starter motor: Model/manufacturer 5UM01/YAMAHA----
Operation voltage 12 V----
Output 0.35 kW----
Armature coil resistance 0.0189–0.0231 Ω at 20 °C (68 °F) ----
Brush overall length 7 mm (0.28 in)3.5 mm (0.14
in)
Brush quantity 2 pcs.----
Spring force 3.92–5.88 N (400–600 g, 14.1–21.2 oz) ----
Commutator diameter 17.6 mm (0.69 in)16.6 mm (0.65
in)
Mica undercut (depth) 1.5 mm (0.06 in) ----
Starter relay: Model/manufacturer 2768090-A/JIDECO----
Amperage rating 180 A----
Coil winding resistance 4.2–4.6 Ω at 20 °C (68 °F) ----
Starting circui t cut-off relay:
Model/manufacturer ACM33221 M38/MATSUSHITA ----
Coil winding resistance 75.69–92.51 Ω at 20 °C (68 °F) ----
Fuse (amperage×quantity): Main fuse 10 A × 1----
Reserve fuse 10 A × 1----
Item
StandardLimit
Part to be tightened Thread size Q'tyTightening torque
Nm m•kg ft•lb
Spark plug M10S × 1.0 1 13 1.3 9.4
Camshaft cap M6 × 1.0 10 10 1.0 7.2
Cylinder head blind plug screw M12 × 1.0 1 28 2.8 20
Cylinder head (stud bolt) M6 × 1.0 2 7 0.7 5.1

2-12
TIGHTENING TORQUES
Cylinder head (stud bolt)M8 × 1.25 1 15 1.5 11
Cylinder head (bolt) M9 × 1.25 4 38 3.8 27
Cylinder head (nut) M6 × 1.0 2 10 1.0 7.2
Cylinder head cover M6 × 1.0 2 10 1.0 7.2
Cylinder M6 × 1.0 1 10 1.0 7.2
Balancer weight M6 × 1.0 2 10 1.0 7.2
Balancer shaft driven gear M14 × 1.0 1 50 5.0 36
Timing chain guide (intake side) M6 × 1.0 2 10 1.0 7.2
Timing chain tensioner M6 × 1.0 2 10 1.0 7.2
Timing chain tensioner cap bolt M6 × 1.0 1 7 0.7 5.1
Impeller M8 × 1.25 1 14 1.4 10
Radiator hose clamp M6 × 1.0 10 2 0.2 1.4
Coolant drain bolt M6 × 1.0 1 10 1.0 7.2
Water pump housing M6 × 1.0 4 10 1.0 7.2
Radiator stay M6 × 1.0 6 10 1.0 7.2
Radiator M6 × 1.0 4 10 1.0 7.2
Radiator pipe M6 × 1.0 1 10 1.0 7.2
Oil pump cover M4 × 0.7 1 2 0.2 1.4
Oil pump M6 × 1.0 3 10 1.0 7.2
Oil filter element drain bolt M6 × 1.0 1 10 1.0 7.2
Oil filter element cover M6 × 1.0 2 10 1.0 7.2
Oil strainer (crankcase) M6 × 1.0 2 10 1.0 7.2
Oil delivery pipe 1 (M10) M10 × 1.25 1 20 2.0 14
Oil delivery pipe 1 (M8) M8 × 1.25 2 18 1.8 13
Oil hose M6 × 1.0 2 8 0.8 5.8
△ Oil hose clamp —2 2 0.2 1.4
Oil strainer (oil tank) M6 × 1.0 1 9 0.9 6.5
Oil tank drain bolt M8 × 1.25 1 18 1.8 13
Oil tank (upper) M6 × 1.0 1 7 0.7 5.1
Oil tank and frame M6 × 1.0 3 9 0.9 6.5
Oil pressure check bolt M6 × 1.0 1 10 1.0 7.2
Carburetor joint M6 × 1.0 2 10 1.0 7.2
Carburetor joint clamp M4 × 0.7 2 3 0.3 2.2
Air filter joint clamp M6 × 1.0 1 3 0.3 2.2
Throttle cable adjust bolt and locknut M6 × 0.75 1 4 0.4 2.9
Throttle cable (pull) M6 × 1.0 1 4 0.4 2.9
Throttle cable (return) M12 × 1.0 1 11 1.1 8.0
Throttle cable cover M5 × 0.8 2 4 0.4 2.9
Hot starter plunger M12 × 1.0 1 2 0.2 1.4
Hot starter cable adjust bolt and locknut M6 × 0.75 1 4 0.4 2.9
△ Air filter case M6 × 1.0 2 8 0.8 5.8
Air filter joint and air filter case M5 × 0.8 1 4 0.4 2.9
Exhaust pipe M8 × 1.25 2 20 2.0 14
△ Exhaust pipe protector M6 × 1.0 3 10 1.0 7.2
Part to be tightened
Thread size Q'tyTightening torque
Nm m•kg ft•lb

2-13
TIGHTENING TORQUES
CHASSIS
△- marked portion shall be checked for torque ti ghtening after break-in or before each race.
△Silencer M8 × 1.25 2 30 3.0 22
Silencer clamp M8 × 1.25 1 16 1.6 11
Spark arrester M5 × 0.8 4 7 0.7 5.1
Silencer cap M5 × 0.8 6 5 0.5 3.6
Air induction pipe M6 × 1.0 1 10 1.0 7.2
Air induction pipe clamp M6 × 1.0 1 4 0.4 2.9
Air cut-off valve assembly and bracket M6 × 1.0 2 10 1.0 7.2
Bracket (air cut-off valve) and frame M6 × 1.0 2 7 0.7 5.1
Crankcase M6 × 1.0 11 12 1.2 8.7
Crankcase bearing stopper M6 × 1.0 11 10 1.0 7.2
Crankcase bearing stopper (crankshaft) M6 × 1.0 4 14 1.4 10
Left crankcase cove r M6 × 1.0 8 10 1.0 7.2
Idle gear cover (starter motor) M6 × 1.0 3 10 1.0 7.2
Idle gear plate M6 × 1.0 2 10 1.0 7.2
Right crankcase cove r M6 × 1.0 6 10 1.0 7.2
Clutch cover M6 × 1.0 7 10 1.0 7.2
Crankcase oil drain bolt M10 × 1.25 1 20 2.0 14
△ Crankshaft end accessing screw M32 × 1.5 1 — — —
△ Timing mark accessing screw M14 × 1.5 1 — — —
Drive chain sprocket cover M6 × 1.0 2 8 0.8 5.8
Kick shaft ratchet wheel guide M6 × 1.0 2 12 1.2 8.7
Kickstarter crank M8 × 1.25 1 33 3.3 24
Primary drive gear M18 × 1.0 1 75 7.5 54
Clutch spring M6 × 1.0 5 10 1.0 7.2
Clutch boss M16 × 1.0 1 60 6.0 43
Clutch cable locknut M8 × 1.25 2 7 0.7 5.1
Push lever shaft M6 × 1.0 1 10 1.0 7.2
Drive sprocket M18 × 1.0 1 75 7.5 54
Drive axle oil seal stopper M6 × 1.0 2 10 1.0 7.2
Segment M8 × 1.25 1 30 3.0 22
Shift guide M6 × 1.0 2 10 1.0 7.2
Stopper lever M6 × 1.0 1 10 1.0 7.2
Shift pedal M6 × 1.0 1 12 1.2 8.7
Part to be tightened
Thread size Q'tyTightening torque
Nm m•kg ft•lb
Part to be tightened Thread size Q'tyTightening torque
Nm m•kg ft•lb
△ Upper bracket and outer tube M8 × 1.25 4 21 2.1 15
△ Lower bracket and outer tube M8 × 1.25 4 21 2.1 15
△ Upper bracket and steeri ng stem M24 × 1.0 1 145 14.5 105
△ Handlebar upper holder and handlebar lower holder M8 × 1.25 4 28 2.8 20
△ Handlebar lower holder and upper bracket M10 × 1.25 2 34 3.4 24
△ Steering stem and steering ring nut M28 × 1.0 1Refer to NOTE.