Page 74 of 676
SPEC
2 - 1
EC200000
SPECIFICATIONS
EC211000
GENERAL SPECIFICATIONS
Model name: YZ250FW (USA, CDN, AUS, NZ)
YZ250F (EUROPE, ZA)
Model code number: 5XCG (USA, CDN)
5XCH (EUROPE)
5XCK (AUS, NZ, ZA)
Dimensions: USA, CDN,
ZA, AUS, NZEUROPE
(Except for F)F
Overall length 2,160 mm
(85.04 in)2,166 mm
(85.28 in)2,165 mm
(85.24 in)
Overall width 825 mm
(32.48 in)← ←
Overall height 1,299 mm
(51.14 in)1,302 mm
(51.26 in)←
Seat height 984 mm
(38.74 in)997 mm
(39.25 in)996 mm
(39.21 in)
Wheelbase 1,469 mm
(57.83 in)← ←
Minimum ground clearance 370 mm
(14.57 in)372 mm
(14.65 in)←
Dry weight:
Without oil and fuel 92.7 kg (204 lb)
Engine:
Engine type Liquid cooled 4-stroke, DOHC
Cylinder arrangement Single cylinder, forward inclined
Displacement 249 cm
3 (8.76 Imp oz, 8.42 US oz)
Bore × stroke 77.0 × 53.6 mm (3.03 × 2.11 in)
Compression ratio 12.5 : 1
Starting system Kickstarter
Lubrication system: Dry sump
2
GENERAL SPECIFICATIONS
Page 81 of 676

SPEC
2 - 8 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 40.4 mm (1.59 in) 39.4 mm
(1.55 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 limit ---- 0.05 mm
(0.002 in)
Kickstarter:
Type Kick and ratchet type ----
Carburetor:
USA, CDNEUROPE, ZA,
AUS, NZ
Type/manufacturer FCR-MX37/
KEIHIN
←----
I. D. mark 5XCG G0 5XCH H0 ----
Main jet (M.J) #178
←----
Main air jet (M.A.J)ø2.0
←----
Jet needle – clip position (J.N) OBEPQ-4
←----
Cutaway (C.A) 1.5
←----
Pilot jet (P.J) #42
←----
Pilot air jet (P.A.J) #105
←----
Pilot outlet (P.O)ø0.9
←----
Pilot screw (example) (P.S) 1-7/8 2-1/8 ----
Bypass (B.P)ø1.0
←----
Valve seat size (V.S)ø3.8
←----
Starter jet (G.S) #72
←----
Leak jet (Acc.P) #80 #70 ----
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 Standard Limit
MAINTENANCE SPECIFICATIONS
Page 82 of 676
SPEC
2 - 9 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 size
Width 120.2 mm (4.7 in) ----
Height 240 mm (9.4 in) ----
Thickness 22 mm (0.9 in) ----
Radiator cap opening pressure 110 kPa (1.1 kg/cm
2, 15.6 psi) ----
Radiator capacity 0.58 L (0.51 Imp qt, 0.61 US qt) ----
Water pump
Type Single-suction centrifugal pump ----Item Standard Limit
MAINTENANCE SPECIFICATIONS
Page 86 of 676

SPEC
2 - 13 Swingarm:
Swingarm free play limit
End ---- 1.0 mm (0.04 in)
Wheel:
Front wheel type Spoke wheel ----
Rear wheel type Spoke wheel ----
Front rim size/material 21 × 1.60/Aluminum ----
Rear rim size/material 19 × 1.85/Aluminum ----
Rim runout limit:
Radial ---- 2.0 mm (0.08 in)
Lateral ---- 2.0 mm (0.08 in)
Drive chain:
Type/manufacturer DID520DMA2 SDH/DAIDO ----
Number of links 111 links + joint ----
Chain slack 48 ~ 58 mm (1.9 ~ 2.3 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. 9.5 mm (0.374 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)5 mm (0.20 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 Standard Limit
MAINTENANCE SPECIFICATIONS
Page 161 of 676

3 - 2
INSP
ADJ
MAINTENANCE INTERVALS
SHIFT FORK, SHIFT CAM, GUIDE BAR
InspectInspect wear
ROTOR NUT
Retighten
EXHAUST PIPE, SILENCER, PRO-
TECTOR
Inspect and retighten
Clean
Replace * Whichever comes first
CRANK
Inspect and clean
CARBURETOR
Inspect, adjust and clean
SPARK PLUG
Inspect and clean
Replace
DRIVE CHAIN
Use chain lube
Chain slack: 48 ~ 58 mm
(1.9 ~ 2.3 in) Lubricate, slack, alignment
Replace
COOLING SYSTEM
Check coolant level and leakage
Check radiator cap operation
Replace coolant Every two years
Inspect hoses
OUTSIDE NUTS AND BOLTS Refer to “STARTING
AND BREAK-IN” section
in the CHAPTER 1. Retighten
AIR FILTER
Clean and lubricate
Use foam air-filter oil or
equivalent oil
Replace
OIL FILTER
Replace
OIL STRAINER
Clean
FRAME
Clean and inspect
FUEL TANK, COCK
Clean and inspect
BRAKES
Adjust lever position and pedal height
Lubricate pivot point
Check brake disc surface
Check fluid level and leakage
Retighten brake disc bolts, caliper
bolts, master cylinder bolts and union
bolts
Replace pads
Replace brake fluid Every one year
FRONT FORKS
Inspect and adjust
Replace oil Suspension oil “S1”
Replace oil sealItemAfter
break-inEvery
race
Every
third
(or
500 km)Every
fifth
(or
1,000 km)As re-
quiredRemarks
3
Page 218 of 676
3 - 25
INSP
ADJREAR BRAKE ADJUSTMENT/
FRONT BRAKE PAD INSPECTION AND REPLACEMENT
EC364002
REAR BRAKE ADJUSTMENT
1. Check:
Brake pedal height a
Out of specification → Adjust.
Brake pedal height
a:
5 mm (0.20 in)
2. Adjust:
Brake pedal height
Pedal height adjustment steps:
Loosen the locknut 1.
Turn the adjusting nut 2 until the pedal
height a is within specified height.
Tighten the locknut.
WARNING
Adjust the pedal height between the
maximum
È and the minimum
É as
shown. (In this adjustment, the bolt
3
end
b should protrude out of the
threaded portion
4 but not be less than
2 mm (0.08 in)
c away from the brake
pedal
5).
After the pedal height adjustment, make
sure that the rear brake does not drag.
È
É
FRONT BRAKE PAD INSPECTION AND
REPLACEMENT
1. Inspect:
Brake pad thickness a
Out of specification → Replace as a set.
Brake pad thickness:
4.4 mm (0.17 in)
: 1.0 mm (0.04 in)
2. Replace:
Brake pad
Brake pad replacement steps:
Remove the pad pin plug 1.
Page 288 of 676
4 - 14
ENGCARBURETOR
Float height
1. Measure:
Float height a
Out of specification → Adjust.
Float height:
8.0 mm (0.31 in)
Measurement and adjustment steps:
Hold the carburetor in an upside down
position.
NOTE:
Slowly tilt the carburetor in the opposite
direction, then take the measurement
when the needle valve aligns with the float
arm.
If the carburetor is level, the weight of the
float will push in the needle valve, resulting
in an incorrect measurement.
Measure the distance between the mating
surface of the float chamber and top of the
float using a vernier calipers.
NOTE:
The float arm should be resting on the nee-
dle valve, but not compressing the needle
valve.
If the float height is not within specification,
inspect the valve seat and needle valve.
If either is worn, replace them both.
If both are fine, adjust the float height by
bending the float tab b on the float.
Recheck the float height.
EC464600
Float
1. Inspect:
Float 1
Damage → Replace.
Page 300 of 676
4 - 20
ENGCARBURETOR
Accelerator pump timing adjustment
Adjustment steps:
NOTE:
In order for the throttle valve height a to
achieve the specified value, tuck under the
throttle valve plate 1 the rod 2 etc. with the
same outer diameter as the specified value.
Throttle valve height:
0.8 mm (0.031 in)
Fully turn in the accelerator pump adjust-
ing screw 3.
Check that the link lever 4 has free play
b by pushing lightly on it.
Gradually turn out the adjusting screw
while moving the link lever until it has no
more free play.
Carburetor installation
1. Install:
Carburetor joint 1
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
2. Install:
Carburetor 1
NOTE:
Install the projection a between the carburetor
joint slots.