YAMAHA YZ250F 2010 Owner's Guide

2-5
MAINTENANCE SPECIFICATIONS
Stem runout limit----0.01 mm
(0.0004 in)
Valve seat width (IN) 0.9–1.1 mm (0.0354–0.0433 in) 1.6 mm (0.0630
in)
Valve seat width (EX) 0.9–1.1 mm (0.0354–0.0433 in) 1.6 mm (0.0630
in)
Valve spring: Free length (IN) 39.76 mm (1.57 in)38.76 mm (1.53
in)
Free length (EX) 37.78 mm (1.49 in)36.78 mm (1.45
in)
Set length (valve closed ) (IN) 28.98 mm (1.14 in) ----
Set length (valve closed ) (EX) 28.30 mm (1.11 in) ----
Compressed force (installed) (IN) 99–114 N at 28.98 mm (9.9–11.4 kg at
28.98 mm, 22.27–25.57 lb at 1.14 in) ----
Compressed force (installed) (EX) 126–145 N at 28.30 mm (12.6–14.5 kg at
28.30 mm, 28.44–31.97 lb at 1.11 in) ----
Tilt limit* (IN) ----2.5°/1.7 mm
(2.5°/0.067 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----
Item
StandardLimit

2-6
MAINTENANCE SPECIFICATIONS
Piston pin bore inside diameter16.002–16.013 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)
Side clearance 0.020–0.055 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 (0.016–0.039 in)2.0 mm (0.08
in)
Item
StandardLimit

2-7
MAINTENANCE SPECIFICATIONS
Clutch:Friction plate thickness 2.9–3.1 mm (0.114–0.122 in)2.8 mm (0.110
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 35.7 mm (1.41 in)34.7 mm (1.37
in)
Quantity 5----
Clutch housing thrust clearance 0.050–0.300 mm (0.0020–0.0118 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----
Carburetor: USA, CDNEUROPE, AUS, NZ,
ZA
Type/manufacturer FCR-MX37/KEIHIN← ----
I. D. mark 17D5 5017D6 60----
Main jet (M.J) #180←----
Main air jet (M.A.J) ø2.0← ----
Jet needle-clip position (J.N) NDJR-4NHKR-4 ----
Cutaway (C.A) 1.5←----
Pilot jet (P.J) #45#42 ----
Pilot air jet (P.A.J) #105← ----
Pilot outlet (P.O) ø0.9←----
Pilot screw (example) (P.S) 1-3/4←----
Bypass (B.P) ø1.0←----
Valve seat size (V.S) ø3.8←----
Starter jet (G.S) #72← ----
Leak jet (Acc.P) #70#110 ----
Float height (F.H) 8 mm (0.31 in)← ----
Engine idle speed 1,900–2,100 r/min← ----
Intake vacuum 29.3–34.7 kPa
(220–260 mmHg,
8.66–9.45 inHg) ←
----
Hot starter lever free play 3–6 mm (0.12–0.24
in) ←
----
Item
StandardLimit

2-8
MAINTENANCE SPECIFICATIONS
CHASSISLubrication 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 121.4 mm (4.8 in)----
Height 235 mm (9.3 in)----
Thickness 28 mm (1.1 in)----
Radiator cap opening pressure 110 kPa (1.1 kg/cm
2, 15.6 psi)----
Radiator capacity (total) 0.64 L (0.56 Imp qt, 0.68 US qt)----
Water pump Type Single-suction centrifugal pump----
Item
StandardLimit
Item StandardLimit
Steering system: Steering bearing type Taper roller bearing----
Front suspension: USA, CDN EUROPE, AUS, NZ, ZA
Front fork travel 300 mm (11.8 in)←----
Fork spring free length 454 mm (17.9 in)←449 mm (17.7
in)
Spring rate, STD K = 4.4 N/mm (0.449 kg/
mm, 25.1 lb/in) K = 4.5 N/mm (0.459 kg/
mm, 25.7 lb/in)----
Optional spring Yes← ----
Oil capacity 541 cm
3 (19.0 lmp oz,
18.3 US oz) 528 cm3 (18.6 lmp oz,
17.9 US oz) ----
Oil grade Suspension oil "S1"←----
Inner tube outer diameter 48 mm (1.89 in)←----
Front fork top end 5 mm (0.20 in)←----
Rear suspension: USA, CDN EUROPE, AUS, NZ, ZA
Shock absorber travel 131.5 mm (5.18 in)←----
Spring free length 260 mm (10.24 in)←----
Fitting length 250 mm (9.84 in)←
Preload length
1.5–20 mm (0.06–0.79
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) ←
----

2-9
MAINTENANCE SPECIFICATIONS
Swingarm:Swingarm free play limitEnd ---- 1.0 mm (0.04
in)
Wheel: Front wheel type Spoke wheel----
Rear wheel type Spoke wheel----
Front rim size/materia l 21 × 1.60/Aluminum ----
Rear rim size/materia l 19 × 1.85/Aluminum ----
Rim runout limit: Radial ---- 2.0 mm (0.08
in)
Lateral ---- 2.0 mm (0.08
in)
Drive chain: USA, CDN EUROPE, AUS, NZ, ZA
Type/manufacturer DID520DMA2 SDH/
DAIDO ←
----
Number of links 111 links + joint 113 links + joint ----
Chain slack 50–60 mm (2.0–2.4 in)←----
Chain length (15 links) ----←242.9 mm
(9.563 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. 9.52 mm (0.375 in)----
Caliper cylinder inside dia. 22.65 mm (0.892 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) Zero mm (Zero in)
----
Clutch lever free play (lever end) 7–12 mm (0.28–0.47 in)----
Throttle grip free play 3–5 mm (0.12–0.20 in)----
Item
StandardLimit

2-10
TIGHTENING TORQUES
ELECTRICAL
TIGHTENING TORQUES
ENGINE
△- marked portion shall be checked for torque ti ghtening after break-in or before each race.
Item StandardLimit
Ignition system: Advancer type Electrical----
CDI: Magneto-model (stator)/manufacturer 17D-50/YAMAHA----
Charging coil 1 resistance (color) 720–1,080 Ωat 20 °C (68 °F)
(Green–Brown) ----
Charging coil 2 resistance (color) 44–66 Ωat 20 °C (68 °F) (Black–Pink) ----
Pickup coil resistance (color) 248–372 Ωat 20 °C (68 °F) (White–Red) ----
CDI unit-model/manufacturer 17D-50/YAMAHA (For USA and CDN) ----
17D-60/YAMAHA (Except for USA and
CDN) ----
Ignition coil: Model/manufacturer 5UL-20/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) ----
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
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 M6 × 1.0 6 10 1.0 7.2
Radiator pipe M6 × 1.0 1 10 1.0 7.2
Oil pump cover M4 × 0.7 1 1.7 0.17 1.2
Oil pump M6 × 1.0 3 10 1.0 7.2

2-11
TIGHTENING TORQUES
Oil filter element drain boltM6 × 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 —1 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 4 0.4 2.9
Oil tank and frame M6 × 1.0 3 9 0.9 6.5
Carburetor joint clamp M5 × 0.8 1 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
Air filter element M6 × 1.0 1 2 0.2 1.4
Exhaust pipe M8 × 1.25 2 20 2.0 14
△ Exhaust pipe protector M6 × 1.0 3 10 1.0 7.2
△ Silencer M8 × 1.25 2 30 3.0 22
Silencer clamp M8 × 1.25 1 14 1.4 10
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
Right crankcase cove r M6 × 1.0 8 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 7 0.7 5.1
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 75 7.5 54
Clutch cable locknut M8 × 1.25 1 7 0.7 5.1
Clutch cable adjust bolt and locknut M6 × 0.75 1 4 0.4 2.9
Push lever shaft M6 × 1.0 1 10 1.0 7.2
Part to be tightened
Thread size Q'tyTightening torque
Nm m•kg ft•lb

2-12
TIGHTENING TORQUES
CHASSIS
△- marked portion shall be checked for torque ti ghtening after break-in or before each race.
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 25
△ Steering stem and steering ring nut M28 × 1.0 1Refer to TIP.
Front fork and damper assembly M51 × 1.5 2 30 3.0 22
Front fork and adjuster M22 × 1.25 2 55 5.5 40
Damper assembly and base valve M42 × 1.5 2 29 2.9 21
Adjuster and damper assembly M12 × 1.25 2 29 2.9 21
Front fork bleed screw and base valve M5 × 0.8 2 1 0.1 0.7
△ Front fork and front fork protector M6 × 1.0 6 5 0.5 3.6
△ Lower bracket and brake hose guide M6 × 1.0 1 9 0.9 6.5
△ Front fork protector and brake hose holder M6 × 1.0 2 8 0.8 5.8
Throttle grip cap M5 × 0.8 2 4 0.4 2.9
△ Front brake master cylinder M6 × 1.0 2 9 0.9 6.5
Brake lever mounting bolt M6 × 1.0 1 6 0.6 4.3
Brake lever mounting nut M6 × 1.0 1 6 0.6 4.3
Brake lever position locknut M6 × 1.0 1 5 0.5 3.6
Clutch lever holder M6 × 1.0 2 5 0.5 3.6
Clutch lever mounting nut M6 × 1.0 1 4 0.4 2.9
Clutch lever position lock nut M5 × 0.8 1 5 0.5 3.6
Hot starter lever holder M5 × 0.8 2 4 0.4 2.9
Front brake master cylinder cap M4 × 0.7 2 2 0.2 1.4
△ Front brake hose union bolt M10 × 1.25 2 30 3.0 22
△ Front brake caliper M8 × 1.25 2 28 2.8 20
Pad pin plug M10 × 1.0 2 3 0.3 2.2
△ Front brake caliper and pad pin M10 × 1.0 1 18 1.8 13
△ Rear brake caliper and pad pin M10 × 1.0 1 18 1.8 13
△ Brake caliper and bleed screw M8 × 1.25 2 6 0.6 4.3
△ Front wheel axle and axle nut M16 × 1.5 1 105 10.5 75
△ Front wheel axle holder M8 × 1.25 4 21 2.1 15

2-13
TIGHTENING TORQUES
△Front brake disc M6 × 1.0 6 12 1.2 8.7
△ Rear brake disc M6 × 1.0 6 14 1.4 10
△ Footrest bracket and frame M10 × 1.25 4 55 5.5 40
△ Brake pedal M8 × 1.25 1 26 2.6 19
△ Rear brake master cylinder M6 × 1.0 2 10 1.0 7.2
Rear brake master cylinder cap M4 × 0.7 2 2 0.2 1.4
△ Rear brake hose union bolt M10 × 1.25 2 30 3.0 22
△ Rear wheel axle and axle nut M22 × 1.5 1 135 13.5 98
△ Nipple (spoke) —72 3 0.3 2.2
△ Rear wheel sprocket M8 × 1.25 6 42 4.2 30
△ Rear brake disc cover M6 × 1.0 2 10 1.0 7.2
△ Rear brake caliper protector M6 × 1.0 2 7 0.7 5.1
Drive chain puller adjust bolt and locknut M8 × 1.25 2 21 2.1 15
Engine mounting:
△ Engine and engine bracket (front) M10 × 1.25 1 53 5.3 38
△ Engine and frame (lower) M10 × 1.25 1 53 5.3 38
△ Upper engine bracket and frame M8 × 1.25 4 34 3.4 25
△ Front engine bracket and frame M8 × 1.25 4 34 3.4 25
△ Engine and engine bracket (upper) M10 × 1.25 2 55 5.5 40
Lower engine guard M6 × 1.0 3 10 1.0 7.2
CDI unit bracket M6 × 1.0 2 7 0.7 5.1
Cable guide and frame M6 × 1.0 2 7 0.7 5.1
△ Pivot shaft and nut M16 × 1.5 1 85 8.5 61
△ Relay arm and swingarm M14 × 1.5 1 70 7.0 50
△ Relay arm and connecting rod M14 × 1.5 1 80 8.0 58
△ Connecting rod and frame M14 × 1.5 1 80 8.0 58
△ Rear shock absorber and frame M10 × 1.25 1 56 5.6 40
△ Rear shock absorber and relay arm M10 × 1.25 1 53 5.3 38
△ Rear frame (upper) M8 × 1.25 2 32 3.2 23
△ Rear frame (lower) M8 × 1.25 2 32 3.2 23
△ Swingarm and brake hose holder M5 × 0.8 4 3 0.3 2.2
Upper drive chain tensioner M8 × 1.25 1 16 1.6 11
Lower drive chain tensioner M8 × 1.25 1 16 1.6 11
Drive chain support M6 × 1.0 3 7 0.7 5.1
△ Seal guard and swingarm M5 × 0.8 4 6 0.6 4.3
△ Fuel tank M6 × 1.0 1 9 0.9 6.5
△ Fuel cock M6 × 1.0 2 4 0.4 2.9
Seat set bracket and fuel tank M6 × 1.0 1 7 0.7 5.1
Fuel tank bracket and fuel tank M6 × 1.0 2 7 0.7 5.1
Side cover set bracket and fuel tank M6 × 1.0 2 7 0.7 5.1
Fitting band set screw and fuel tank M6 × 1.0 1 7 0.7 5.1
△ Air scoop and fuel tank M6 × 1.0 2 7 0.7 5.1
△ Air scoop and radiator guard M6 × 1.0 4 7 0.7 5.1
Air scoop and frame M6 × 1.0 2 7 0.7 5.1
Part to be tightened
Thread size Q'tyTightening torque
Nm m•kg ft•lb

2-14
TIGHTENING TORQUES
1. First, tighten the steering ring nut approximately 38 Nm (3.8 m•kg, 27 ft•lb) by using the steering nut wrench, then loosen
the steering ring nut one turn.
2. Retighten the steering ring nut 7 Nm (0.7 m•kg, 5.1 ft•lb).
ELECTRICAL Radiator mounting boss and frame
M10 × 1.25 2 20 2.0 14
△ Front fender M6 × 1.0 4 10 1.0 7.2
△ Rear fender (front) M6 × 1.0 2 7 0.7 5.1
△ Rear fender (rear) M6 × 1.0 2 16 1.6 11
△ Side cover M6 × 1.0 2 7 0.7 5.1
Seat M8 × 1.25 2 23 2.3 17
△ Number plate M6 × 1.0 1 7 0.7 5.1
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
Stator M6 × 1.0 3 10 1.0 7.2
Rotor M12 × 1.25 1 56 5.6 40
Neutral switch M5 × 0.8 2 4 0.4 2.9