1-15
TORQUE-CHECK POINTS
TORQUE-CHECK POINTS
Concerning the tightening torque, refer to "TIGHTENING TORQUES" section in the CHAPTER 2.
Frame construction Frame to rear frame
Combined seat and fuel tank Fuel tank to frame
Exhaust system Silencer to rear frame
Engine mounting Frame to engine
Engine bracket to engine
Engine bracket to frame
Steering Steering stem to handlebar Steering stem to frame
Steering stem to upper bracket
Upper bracket to handlebar
Suspension Front Steering stem to front fork Front fork to upper bracket
Front fork to lower bracket
Rear For link type Assembly of links
Link to frame
Link to rear shock absorber
Link to swingarm
Installation of rear shock absorber Rear shock absorber to frame
Installation of swingarm Tightening of pivot shaft
Wheel Installation of wheel Front Tightening of wheel axle
Tightening of axle holder
Rear Tightening of wheel axle
Wheel to rear wheel sprocket
Brake Front Brake caliper to front fork
Brake disc to wheel
Tightening of union bolt
Brake master cylinder to handlebar
Tightening of bleed screw
Tightening of brake hose holder
Rear Brake pedal to frame
Brake disc to wheel
Tightening of union bolt
Brake master cylinder to frame
Tightening of bleed screw
Tightening of brake hose holder
Fuel system Fuel tank to fuel cock
Lubrication system Tightening of oil hose clamp
2-1
GENERAL SPECIFICATIONS
SPECIFICATIONS
GENERAL SPECIFICATIONS
Model name: YZ250FB (USA, CDN, AUS, NZ)
YZ250F (EUROPE, ZA)
Model code number: 17D9 (USA,CDN)
17DA (EUROPE)
17DC (AUS, NZ, ZA)
Dimensions: USA, CDN EUROPE AUS, NZ, ZA
Overall length 2,170 mm (85.43
in)2,163 mm (85.16
in)2,161 mm (85.08
in)
Overall width 825 mm (32.48 in)←←
Overall height 1,307 mm (51.46
in)1,306 mm (51.42
in)←
Seat height 992 mm (39.06 in)←990 mm (38.98 in)
Wheelbase 1,477 mm (58.15
in)1,468 mm (57.80
in)←
Minimum ground clearance 378 mm (14.88 in)←377 mm (14.84 in)
Weight:
Curb weight 103 kg (227 lb)
Engine:
Engine type Liquid cooled 4-stroke, DOHC
Cylinder arrangement Single cylinder
Displacement 250 cm
3 (8.80 Imp oz, 8.45 US oz)
Bore × stroke 77.0 × 53.6 mm (3.03 × 2.11 in)
Compression ratio 13.5 : 1
Starting system Kickstarter
Lubrication system: Dry sump
Oil type or grade:
Engine oil Recommended brand: YAMALUBE
SAE10W-30, SAE10W-40, SAE10W-50
SAE15W-40, SAE20W-40 or SAE20W-50
API service SG type or higher,
JASO standard MA
Oil capacity:
Engine oil
Periodic oil change 0.95 L (0.84 Imp qt, 1.00 US qt)
With oil filter replacement 1.05 L (0.92 Imp qt, 1.11 US qt)
Total amount 1.20 L (1.06 Imp qt, 1.27 US qt)
Coolant capacity (including all routes): 1.00 L (0.88 Imp qt, 1.06 US qt)
Air filter: Wet type element
Fuel:
Type Premium unleaded gasoline only with a research octane
number of 95 or higher.
Tank capacity 6.4 L (1.4 Imp gal, 1.69 US gal)
2
2-2
GENERAL SPECIFICATIONS
Carburetor:Type FCR-MX39
Manufacturer KEIHIN
Spark plug: Type/manufacturer CR8E/NGK (resistance type)
Gap 0.7–0.8 mm (0.028–0.031 in)
Clutch type: Wet, multiple-disc
Transmission: USA, CDN EUROPE, AUS, NZ, ZA Primary reduction system Gear ←
Primary reduction ratio 3.353 (57/17) ←
Final drive Chain ←
Secondary reduction ratio 3.846 (50/13) 3.923 (51/13)
Transmission type Constant mesh, 5-speed ←
Operation Left foot operation ←
Gear ratio:
1st 2.143 (30/14) ←
2nd 1.750 (28/16) ←
3rd 1.444 (26/18) ←
4th 1.222 (22/18) ←
5th 1.042 (25/24) ←
Chassis: USA, CDN EUROPE AUS, NZ, ZA
Frame type Semi double cra-
dle ←←
Caster angle 27.21°27.12°27.32°
Trail 121.3 mm (4.78
in) 119.9 mm (4.72
in)122.1 mm (4.81
in)
Tire:
Type With tube
Size (front) 80/100-21 51M
Size (rear) 100/90-19 57M
Tire pressure (front and rear) 100 kPa (1.0 kgf/cm
2, 15 psi)
Brake:
Front brake type Single disc brake
Operation Right hand operation
Rear brake type Single disc brake
Operation Right foot operation
Suspension: Front suspension Telescopic fork
Rear suspension Swingarm (link type monocross suspension)
Shock absorber: Front shock absorber Coil spring/oil damper
Rear shock absorber Coil spring/gas, oil damper
Wheel travel: USA, CDN EUROPE, AUS, NZ, ZA Front wheel travel 300 mm (11.8 in) ←
Rear wheel travel 317 mm ( 12.5 in) 312 mm (12.3 in)
Electrical: Ignition system CDI magneto
2-6
MAINTENANCE SPECIFICATIONS
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)
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 Standard Limit
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 size
Width 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 Standard Limit
Item Standard Limit
Steering system:
Steering bearing typeTaper 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 = 4.5 N/mm (0.459 kg/
mm, 25.7 lb/in)←----
Optional spring Yes←----
Oil capacity 543 cm
3 (19.1 lmp oz,
18.4 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 132.0 mm (5.20 in)←----
Spring free length 260 mm (10.24 in)←----
Fitting length 250 mm (9.84 in)←
Preload length
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)←----
2-10
TIGHTENING TORQUES
ELECTRICAL
TIGHTENING TORQUES
ENGINE
△- marked portion shall be checked for torque tightening after break-in or before each race.
Item Standard Limit
Ignition system:
Advancer type Electrical ----
CDI:
Magneto-model (stator)/manufacturer 17D-51/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-90/YAMAHA ----
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) ----
ItemThread
sizeQ'ty Tightening torque Remarks
Spark plug M10S 1 13 Nm (1.3 m•kg, 9.4 ft•lb)
Camshaft cap M6 10 10 Nm (1.0 m•kg, 7.2 ft•lb)
Cylinder head blind plug screw M12 1 28 Nm (2.8 m•kg, 20 ft•lb)
Cylinder head (stud bolt) M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
Cylinder head (stud bolt) M8 1 15 Nm (1.5 m•kg, 11 ft•lb)
Cylinder head (bolt) M9 4 38 Nm (3.8 m•kg, 27 ft•lb)
Cylinder head (nut) M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Cylinder head cover M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Cylinder M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Balancer weight M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Balancer shaft driven gear M14 1 50 Nm (5.0 m•kg, 36 ft•lb) Lock washer
Timing chain guide (intake side) M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Timing chain tensioner M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Timing chain tensioner cap bolt M6 1 7 Nm (0.7 m•kg, 5.1 ft•lb)
Impeller M8 1 14 Nm (1.4 m•kg, 10 ft•lb)
Radiator hose clamp M6 10 2 Nm (0.2 m•kg, 1.4 ft•lb)
Coolant drain bolt M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)Copper
washer
Water pump housing M6 4 10 Nm (1.0 m•kg, 7.2 ft•lb)
Radiator M6 6 10 Nm (1.0 m•kg, 7.2 ft•lb)
Radiator pipe M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Oil pump cover M4 1 1.7 Nm (0.17 m•kg, 1.2 ft•lb)
Oil pump M6 3 10 Nm (1.0 m•kg, 7.2 ft•lb)
Oil filter element drain bolt M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
3-6
ENGINE
ENGINE
CHECKING THE COOLANT LEVEL
Do not remove the radiator cap
"1", drain bolt and hoses when the
engine and radiator are hot. Scald-
ing hot fluid and steam may be
blown out under pressure, which
could cause serious injury. When
the engine has cooled, place a
thick towel over the radiator cap,
slowly rotate the cap counter-
clockwise to the detent. This pro-
cedure allows any residual
pressure to escape. When the
hissing sound has stopped, press
down on the cap while turning
counterclockwise and remove it.
Hard water or salt water is harmful
to the engine parts. You may use
distilled water, if you can't get soft
water.
1. Place the machine on a level
place, and hold it in an upright po-
sition.
2. Remove:
• Radiator cap
3. Check:
• Coolant level "a"
Coolant level low→Add coolant.
1. Radiator
CHANGING THE COOLANT
Do not remove the radiator cap
when the engine is hot.
Take care so that coolant does not
splash on painted surfaces. If it
splashes, wash it away with water.
1. Place a container under the en-
gine.
2. Remove:
• Coolant drain bolt "1"
3. Remove:
• Radiator cap
Drain the coolant completely.
4. Clean:
• Cooling system
Thoroughly flush the cooling sys-
tem with clean tap water.
5. Install:
• Copper washer
• Coolant drain bolt
6. Fill:
• Radiator
•Engine
To specified level.
• Do not mix more than one type of
ethylene glycol antifreeze con-
taining corrosion inhibitors for
aluminum engine.
• Do not use water containing im-
purities or oil.
Handling notes of coolant:
The coolant is harmful so it should be
handled with special care.
• When coolant splashes to your
eye.
Thoroughly wash your eye with
water and see your doctor.
• When coolant splashes to your
clothes.
Quickly wash it away with water
and then with soap.
• When coolant is swallowed.
Quickly make him vomit and take
him to a doctor.
7. Install:
• Radiator cap
Start the engine and warm it up
for a several minutes.
8. Check:
• Coolant level
Coolant level low→Add coolant.
CHECKING THE RADIATOR CAP
1. Inspect:
• Seal (radiator cap) "1"
• Valve and valve seat "2"
Crack/damage→Replace.
Exist fur deposits "3" →Clean or
replace.
CHECKING THE RADIATOR CAP
OPENING PRESSURE
1. Attach:
• Radiator cap tester "1" and adapt-
er "2"
Apply water on the radiator cap seal.
Coolant drain bolt:
10 Nm (1.0 m•kg, 7.2
ft•lb)
Recommended coolant:
High quality ethylene
glycol anti-freeze con-
taining anti-corrosion
for aluminum engine
Coolant "1" and water
(soft water) "2" mixing ra-
tio:
50%/50%
Coolant capacity:
1.00 L (0.88 Imp qt, 1.06
US qt)
Radiator cap tester:
YU-24460-01/90890-
01325
Radiator cap tester
adapter:
YU-33984/90890-01352
3-9
ENGINE
6. Apply:
• Lithium soap base grease
On the matching surface "a" on air
filter element.
7. Install:
• Air filter element "1"
• Washer
• Fitting bolt
Align the projection "a" on filter guide
with the hole "b" in air filter case.
CHECKING THE ENGINE OIL
LEVEL
1. Start the engine, warm it up for
several minutes, and then turn off
the engine and wait for five min-
utes.
2. Place the machine on a level
place and hold it up on upright po-
sition by placing the suitable
stand under the engine.
3. Inspect:
• Oil level
The engine oil level should be be-
tween the minimum level mark "a"
and maximum level mark "b".
Below the minimum level mark →
Add the recommended engine oil
to the proper level.
• Engine oil also lubricates the
clutch and the wrong oil types or
additives could cause clutch
slippage. Therefore, do not add
any chemical additives or use en-
gine oils with a grade of CD or
higher and do not use oils la-
beled "ENERGY CONSERVING
II".
• Do not allow foreign materials to
enter the crankcase.
4. Install:
• Oil tank cap
5. Start the engine and let it warm up
for several minutes.
6. Turn off the engine and inspect
the oil level once again.
Wait a few minutes until the oil settles
before inspecting the oil level.
CHANGING THE ENGINE OIL
1. Start the engine and warm it up
for several minutes, and then turn
off the engine and wait for five
minute.
2. Place the machine on a level
place and hold it on upright posi-
tion by placing the suitable stand
under the engine.
3. Place a suitable container under
the engine.4. Remove:
• Lower engine guard "1"
• Bolt (oil tank) "2"
• Washer "3"
• Oil filler cap "4"
• Oil tank drain bolt "5"
• Crankcase oil drain bolt "6"
• Oil filter element drain bolt "7"
Drain the crankcase and oil tank
of its oil.
5. Remove:
• Oil hose clamp "1"
• Bolt (oil hose)
• Oil hose "2"
• Oil strainer "3"
6. Inspect:
• Oil strainer
Clogged→Blow.
7. If the oil filter is to be replaced dur-
ing this oil change, remove the fol-
lowing parts and reinstall them. Fitting bolt:
2 Nm (0.2 m•kg, 1.4
ft•lb)
Recommended brand:
YAMALUBE
Recommended engine
oil type
SAE10W-30, SAE 10W-
40, SAE 10W-50, SAE
15W-40, SAE 20W-40 or
SAE 20W-50
Recommended engine
oilgrade
API service SG type or
higher, JASO standard
MA