CONTENTS
CHAPTER 1
GENERAL
INFORMATION
LOCATION OF
IMPORTANT LABELS ..... 1-1
DESCRIPTION ................. 1-5
CONSUMER
INFORMATION................. 1-6
INCLUDED PARTS .......... 1-6
IMPORTANT
INFORMATION................. 1-6
CHECKING OF
CONNECTION .................. 1-7
SPECIAL TOOLS ............. 1-8
CONTROL
FUNCTIONS ................... 1-12
STARTING AND
BREAK-IN ...................... 1-13
TORQUE-CHECK
POINTS........................... 1-15
CLEANING AND
STORAGE ...................... 1-16
CHAPTER 2
SPECIFICATIONS
GENERAL
SPECIFICATIONS ............ 2-1
MAINTENANCE
SPECIFICATIONS ............ 2-3
TIGHTENING
TORQUES ...................... 2-10
LUBRICATION
DIAGRAMS .................... 2-16
CABLE ROUTING
DIAGRAM ....................... 2-18
CHAPTER 3
REGULAR
INSPECTION AND
ADJUSTMENTS
MAINTENANCE
INTERVALS ...................... 3-1
PRE-OPERATION
INSPECTION AND
MAINTENANCE................ 3-5
ENGINE ............................ 3-6
CHASSIS ........................ 3-14
ELECTRICAL ................. 3-24
CHAPTER 4
ENGINE
SEAT, FUEL TANK AND
SIDE COVERS.................. 4-1
EXHAUST PIPE AND
SILENCER ........................ 4-3
RADIATOR ....................... 4-7
CARBURETOR................. 4-9
CAMSHAFTS.................. 4-16
CYLINDER HEAD........... 4-21
VALVES AND VALVE
SPRINGS ........................ 4-23
CYLINDER AND
PISTON ........................... 4-27
CLUTCH ......................... 4-31
OIL FILTER ELEMENT
AND WATER PUMP ....... 4-35
BALANCER .................... 4-40
OIL PUMP ....................... 4-42
KICK SHAFT AND
SHIFT SHAFT ................. 4-46
CDI MAGNETO............... 4-51
ENGINE REMOVAL ....... 4-53
CRANKCASE AND
CRANKSHAFT ............... 4-57
TRANSMISSION,
SHIFT CAM AND
SHIFT FORK................... 4-63
CHAPTER 5
CHASSIS
FRONT WHEEL AND
REAR WHEEL ..................5-1
FRONT BRAKE AND
REAR BRAKE ..................5-6
FRONT FORK .................5-16
HANDLEBAR..................5-24
STEERING ......................5-28
SWINGARM ....................5-31
REAR SHOCK
ABSORBER ....................5-36
CHAPTER 6
ELECTRICAL
ELECTRICAL
COMPONENTS AND
WIRING DIAGRAM ...........6-2
IGNITION SYSTEM...........6-3
THROTTLE POSITION
SENSOR SYSTEM ...........6-6
CHAPTER 7
TUNING
ENGINE.............................7-1
CHASSIS ..........................7-6
1-8
SPECIAL TOOLS
SPECIAL TOOLS
The proper special tools are necessary for complete and accurate tune-up and assembly. Using the correct special tool will
help prevent damage caused by the use of improper tools or improvised techniques. The shape and part number used for
the special tool differ by country, so two types are provided. Refer to the list provided to avoid errors when placing an order.
• For U.S.A. and Canada, use part number starting with "YM-", "YU-" or "ACC-".
• For others, use part number starting with "90890-".
Tool name/Part number How to use Illustration
Crankcase separating tool
YU-1135-A, 90890-01135These tool is used to remove the
crankshaft from either case.
Flywheel puller
YM-1189, 90890-01189This tool is used to remove the fly-
wheel magneto.
Rotor holding tool
YU-1235, 90890-01235This tool is used when loosening or
tightening the flywheel magneto se-
curing nut.
Dial gauge and stand
YU-3097, 90890-01252
Stand
YU-1256These tools are used to check each
part for runout or bent.
Crankshaft installing tool
Crankshaft installing pot
YU-90050, 90890-01274
Crankshaft installing bolt
YU-90050, 90890-01275
Spacer (crankshaft installer)
YU-91044, 90890-04081
Adapter (M12)
YU-90063, 90890-01278These tools are used to install the
crankshaft.
Piston pin puller set
YU-1304, 90890-01304 This tool is used to remove the pis-
ton pin.
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
1-16
CLEANING AND STORAGE
CLEANING AND STORAGE
CLEANING
Frequent cleaning of your machine
will enhance its appearance, maintain
good overall performance, and ex-
tend the life of many components.
1. Before washing the machine,
block off the end of the exhaust
pipe to prevent water from enter-
ing. A plastic bag secured with a
rubber band may be used for this
purpose.
2. If the engine is excessively
greasy, apply some degreaser to
it with a paint brush. Do not apply
degreaser to the chain, sprockets,
or wheel axles.
3. Rinse the dirt and degreaser off
with a garden hose; use only
enough pressure to do the job.
Do not use high-pressure washers
or steam-jet cleaners since they
cause water seepage and deterio-
ration seals.
4. After the majority of the dirt has
been hosed off, wash all surfaces
with warm water and a mild deter-
gent. Use an old toothbrush to
clean hard-to-reach places.
5. Rinse the machine off immediate-
ly with clean water, and dry all
surfaces with a soft towel or cloth.
6. Immediately after washing, re-
move excess water from the
chain with a paper towel and lubri-
cate the chain to prevent rust.
7. Clean the seat with a vinyl uphol-
stery cleaner to keep the cover
pliable and glossy.
8. Automotive wax may be applied
to all painted or chromed surfac-
es. Avoid combination cleaner-
waxes, as they may contain abra-
sives.
9. After completing the above, start
the engine and allow it to idle for
several minutes.STORAGE
If your machine is to be stored for 60
days or more, some preventive mea-
sures must be taken to avoid deterio-
ration. After cleaning the machine
thoroughly, prepare it for storage as
follows:
1. Drain the fuel tank, fuel lines, and
the carburetor float bowl.
2. Remove the spark plug, pour a ta-
blespoon of SAE 10W-40 motor
oil in the spark plug hole, and re-
install the plug. With the engine
stop switch pushed in, kick the en-
gine over several times to coat the
cylinder walls with oil.
3. Remove the drive chain, clean it
thoroughly with solvent, and lubri-
cate it. Reinstall the chain or store
it in a plastic bag tied to the frame.
4. Lubricate all control cables.
5. Block the frame up to raise the
wheels off the ground.
6. Tie a plastic bag over the exhaust
pipe outlet to prevent moisture
from entering.
7. If the machine is to be stored in a
humid or salt-air environment,
coat all exposed metal surfaces
with a film of light oil. Do not apply
oil to rubber parts or the seat cov-
er.
Make any necessary repairs before
the machine is stored.
2-1
GENERAL SPECIFICATIONS
SPECIFICATIONS
GENERAL SPECIFICATIONS
Model name: YZ250FD (USA, CDN, AUS, NZ)
YZ250F (EUROPE, ZA)
Model code number: 17DH (USA,CDN)
17DJ (EUROPE)
17DL (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
2-9
MAINTENANCE SPECIFICATIONS
Swingarm:
Swingarm free play limit
End ---- 1.0 mm (0.04
in)
Wheel:
Front wheel type Spoke wheel ----
Rear wheel typeSpoke 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: USA, CDN EUROPE, AUS, NZ, ZA
Type/manufacturer DID520DMA2 SDH/
DAIDO←----
Number of links 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)0 mm (0 in) ----
Clutch lever free play (lever end) 7–12 mm (0.28–0.47 in) ----
Throttle grip free play3–5 mm (0.12–0.20 in) ---- Item Standard Limit
2-11
TIGHTENING TORQUES
Oil filter element cover M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Oil strainer (crankcase) M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Oil delivery pipe 1 (M10) M10 1 20 Nm (2.0 m•kg, 14 ft•lb)Copper
washer
Oil delivery pipe 1 (M8) M8 2 18 Nm (1.8 m•kg, 13 ft•lb)Copper
washer
△Oil hose M6 3 8 Nm (0.8 m•kg, 5.8 ft•lb)
Oil hose clamp — 1 2 Nm (0.2 m•kg, 1.4 ft•lb)
Oil strainer (oil tank) M6 1 9 Nm (0.9 m•kg, 6.5 ft•lb)
Oil tank drain bolt M8 1 18 Nm (1.8 m•kg, 13 ft•lb)
Oil tank (upper) M6 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Oil tank and frame M6 3 9 Nm (0.9 m•kg, 6.5 ft•lb)
Carburetor joint clamp M5 1 3 Nm (0.3 m•kg, 2.2 ft•lb)
Air filter joint clamp M6 1 3 Nm (0.3 m•kg, 2.2 ft•lb)
Throttle cable (pull) M6 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Throttle cable (return) M12 1 11 Nm (1.1 m•kg, 8.0 ft•lb)
Throttle cable cover M5 2 4 Nm (0.4 m•kg, 2.9 ft•lb)
Hot starter plunger M12 1 2 Nm (0.2 m•kg, 1.4 ft•lb)
Hot starter cable adjust bolt and locknut M6 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
△Air filter case M6 2 8 Nm (0.8 m•kg, 5.8 ft•lb)
Air filter joint and air filter case M5 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Air filter element M6 1 2 Nm (0.2 m•kg, 1.4 ft•lb)
Exhaust pipe M8 2 20 Nm (2.0 m•kg, 14 ft•lb)
△Exhaust pipe protector M6 3 10 Nm (1.0 m•kg, 7.2 ft•lb)
△Silencer M8 2 30 Nm (3.0 m•kg, 22 ft•lb)
Silencer clamp M8 1 14 Nm (1.4 m•kg, 10 ft•lb)
Crankcase M6 11 12 Nm (1.2 m•kg, 8.7 ft•lb)
Crankcase bearing stopper M6 11 10 Nm (1.0 m•kg, 7.2 ft•lb)
Crankcase bearing stopper (crankshaft) M6 4 14 Nm (1.4 m•kg, 10 ft•lb) Stake.
Left crankcase cover M6 8 10 Nm (1.0 m•kg, 7.2 ft•lb)
Right crankcase cover M6 8 10 Nm (1.0 m•kg, 7.2 ft•lb)
Clutch cover M6 7 10 Nm (1.0 m•kg, 7.2 ft•lb)
Crankcase oil drain bolt M10 1 20 Nm (2.0 m•kg, 14 ft•lb)Copper
washer
△Crankshaft end accessing screw M32 1 —
△Timing mark accessing screw M14 1 —
△Drive chain sprocket cover M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
Kick shaft ratchet wheel guide M6 2 12 Nm (1.2 m•kg, 8.7 ft•lb) Lock washer
Kickstarter crank M8 1 33 Nm (3.3 m•kg, 24 ft•lb)
Primary drive gear M18 1 75 Nm (7.5 m•kg, 54 ft•lb) Lock washer
Clutch spring M6 5 10 Nm (1.0 m•kg, 7.2 ft•lb)
Clutch boss M16 1 75 Nm (7.5 m•kg, 54 ft•lb) Lock washer
Clutch cable locknut M8 1 7 Nm (0.7 m•kg, 5.1 ft•lb)
Clutch cable adjust bolt and locknutM6 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Push lever shaft M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb) ItemThread
sizeQ'ty Tightening torque Remarks