2009 YAMAHA YZ250F clutch

CONTENTS
CHAPTER 1
GENERAL
INFORMATION
DESCRIPTION ................. 1-1
MACHINE
IDENTIFICATION ............. 1-2
INCLUDED PARTS .......... 1-2
IMPORTANT
INFORMATION................. 1-2
CHECKING OF
CONNECTION .................. 1-3
SPECIAL TOOLS ............. 1-4
CONTROL FUNCTIONS .. 1-8
STARTING AND
BREAK-IN ........................ 1-8
TORQUE-CHECK
POINTS........................... 1-11
CLEANING AND
STORAGE ...................... 1-12
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 ....................... 4-5
CARBURETOR................. 4-7
CAMSHAFTS.................. 4-14
CYLINDER HEAD........... 4-19
VALVES AND VALVE
SPRINGS ........................ 4-21
CYLINDER AND
PISTON ........................... 4-25
CLUTCH ......................... 4-29
OIL FILTER ELEMENT
AND WATER PUMP ....... 4-33
BALANCER .................... 4-37
OIL PUMP ....................... 4-39
KICK SHAFT AND
SHIFT SHAFT ................. 4-42
CDI MAGNETO............... 4-47
ENGINE REMOVAL ....... 4-49
CRANKCASE AND
CRANKSHAFT ............... 4-53
TRANSMISSION,
SHIFT CAM AND
SHIFT FORK................... 4-59
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

1-1
DESCRIPTION
GENERAL INFORMATION
DESCRIPTION
• The machine you have purchased may differ slightly from those shown in the following.
• Designs and specifications are subject to change without notice.
1. Clutch lever
2. Hot starter lever
3. Front brake lever
4. Throttle grip
5. Radiator cap
6. Fuel tank cap
7. Engine stop switch
8. Kickstarter crank
9. Fuel tank
10. Radiator
11. Coolant drain bolt
12. Rear brake pedal
13. Valve joint14. Fuel cock
15. Cold starter knob
16. Drive chain
17. Air filter
18. Oil level check window
19. Shift pedal
20. Front fork
1

1-6
SPECIAL TOOLS
Timing light
YM-33277-A, 90890-03141 This tool is necessary for checking
ignition timing.
Valve spring compressor
YM-4019, 90890-04019 This tool is needed to remove and
install the valve assemblies.
Clutch holding tool
YM-91042, 90890-04086This tool is used to hold the clutch
when removing or installing the
clutch boss securing nut.
Valve guide remover
Intake 4.0 mm (0.16 in)
Exhaust 4.5 mm (0.18 in)
YM-4111, 90890-04111
YM-4116, 90890-04116This tool is needed to remove and
install the valve guide.
Valve guide installer
Intake 4.0 mm (0.16 in)
Exhaust 4.5 mm (0.18 in)
YM-4112, 90890-04112
YM-4117, 90890-04117This tool is needed to install the
valve guide.
Valve guide reamer
Intake 4.0 mm (0.16 in)
Exhaust 4.5 mm (0.18 in)
YM-4113, 90890-04113
YM-4118, 90890-04118This tool is needed to rebore the
new valve guide. Tool name/Part number How to use Illustration

1-8
CONTROL FUNCTIONS
CONTROL FUNCTIONS
ENGINE STOP SWITCH
The engine stop switch "1" is located
on the left handlebar. Continue push-
ing the engine stop switch till the en-
gine comes to a stop.
CLUTCH LEVER
The clutch lever "1" is located on the
left handlebar; it disengages or en-
gages the clutch. Pull the clutch lever
to the handlebar to disengage the
clutch, and release the lever to en-
gage the clutch. The lever should be
pulled rapidly and released slowly for
smooth starts.
SHIFT PEDAL
The gear ratios of the constant-mesh
5 speed transmission are ideally
spaced. The gears can be shifted by
using the shift pedal "1" on the left
side of the engine.
KICKSTARTER CRANK
Rotate the kickstarter crank "1" away
from the engine. Push the starter
down lightly with your foot until the
gears engage, then kick smoothly
and forcefully to start the engine. This
model has a primary kickstarter crank
so the engine can be started in any
gear if the clutch is disengaged. In
normal practices, however, shift to
neutral before starting.THROTTLE GRIP
The throttle grip "1" is located on the
right handlebar; it accelerates or de-
celerates the engine. For accelera-
tion, turn the grip toward you; for
deceleration, turn it away from you.
FRONT BRAKE LEVER
The front brake lever "1" is located on
the right handlebar. Pull it toward the
handlebar to activate the front brake.
REAR BRAKE PEDAL
The rear brake pedal "1" is located on
the right side of the machine. Press
down on the brake pedal to activate
the rear brake.
FUEL COCK
The fuel cock supplies fuel from the
tank to carburetor and also filters the
fuel. The fuel cock has the two posi-
tions:
OFF:
With the lever in this position, fuel will
not flow. Always return the lever to
this position when the engine is not
running.
ON:
With the lever in this position, fuel
flows to the carburetor. Normal riding
is done with the lever in this position.COLD STARTER KNOB
When cold, the engine requires a
richer air-fuel mixture for starting. A
separate starter circuit, which is con-
trolled by the cold starter knob "1",
supplies this mixture. Pull the cold
starter knob out to open the circuit for
starting. When the engine has
warmed up, push it in to close the cir-
cuit.
HOT STARTER LEVER
The hot starter lever "1" is used when
starting a warm engine. Use the hot
starter lever when starting the engine
again immediately after it was
stopped (the engine is still warm).
Pulling the hot starter lever injects
secondary air to thin the air-fuel mix-
ture temporarily, allowing the engine
to be started more easily.
STARTING AND BREAK-IN
FUEL
Always use the recommended fuel as
stated below. Also, be sure to use
new gasoline the day of a race.
Use only unleaded gasoline. The
use of leaded gasoline will cause
severe damage to the engine inter-
nal parts such as valves, piston
rings, and exhaust system, etc.
Recommended fuel:
Premium unleaded
gasoline only with a re-
search octane number
of 95 or higher.

2-2
GENERAL SPECIFICATIONS
Coolant capacity (including all routes): 0.99 L (0.87 Imp qt, 1.05 US qt)
Air filter: Wet type element
Fuel:
Type Premium unleaded gasoline only with a research octane
number of 95 or higher.
Tank capacity 7.0 L (1.54 Imp gal, 1.85 US gal)
Carburetor:
Type FCR-MX37
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 57/17 (3.353)←
Secondary reduction system Chain drive←
Secondary reduction ratio 49/13 (3.769) 51/13 (3.923)
Transmission type Constant mesh, 5-speed←
Operation Left foot operation←
Gear ratio:
1st 30/14 (2.143)←
2nd 28/16 (1.750)←
3rd 29/20 (1.450)←
4th 27/22 (1.227)←
5th 25/24 (1.042)←
Chassis: USA, CDN EUROPE AUS, NZ, ZA
Frame type Semi double cra-
dle←←
Caster angle 27.2° 26.9° 27.1°
Trail 117.8 mm (4.64
in)115.0 mm (4.53
in)117.2 mm (4.61
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)

2-7
MAINTENANCE SPECIFICATIONS
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) 2.8 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 0.10–0.35 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, AUS, NZ,
ZA
Type/manufacturer FCR-MX37/KEIHIN←----
I. D. mark 5XCR R0 5XCS S0 ----
Main jet (M.J) #178←----
Main air jet (M.A.J) ø2.0←----
Jet needle-clip position (J.N) NHKR-4 NFLR-5 ----
Cutaway (C.A) 1.5←----
Pilot jet (P.J) #42 #45 ----
Pilot air jet (P.A.J) #105←----
Pilot outlet (P.O) ø0.9←----
Pilot screw (example) (P.S) 2←----
Bypass (B.P) ø1.0←----
Valve seat size (V.S) ø3.8←----
Starter jet (G.S) #72←----
Leak jet (Acc.P) #70←----
Float height (F.H) 8 mm (0.31 in)←----
Engine idle speed 1,900–2,100 r/min←---- Item Standard Limit

2-10
TIGHTENING TORQUES
ELECTRICAL
TIGHTENING TORQUES
ENGINE
△- marked portion shall be checked for torque tightening after break-in or before each race.
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 Standard Limit
Item Standard Limit
Ignition system:
Advancer type Electrical ----
CDI:
Magneto-model (stator)/manufacturer 5XC-10/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 5XC-R0/YAMAHA (For USA and CDN) ----
5XC-S0/YAMAHA (Except for USA and
CDN)----
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) ----
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

2-11
TIGHTENING TORQUES
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
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 — 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 7 0.7 5.1
Oil tank and frame M6 × 1.0 3 9 0.9 6.5
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
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 16 1.6 11
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
Oil level check window holder M6 × 1.0 1 10 1.0 7.2
Left crankcase cover M6 × 1.0 8 10 1.0 7.2
Right crankcase cover 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 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 7.2Part to be tightened Thread size Q'tyTightening torque
Nm m•kg ft•lb