2006 YAMAHA YZ250F steering

CHAPTER 4
ENGINE
SEAT, FUEL TANK
AND SIDE COVERS...................................4-1
EXHAUST PIPE AND SILENCER..............4-3
RADIATOR.................................................4-6
CARBURETOR...........................................4-9
CAMSHAFTS............................................4-22
CYLINDER HEAD.....................................4-31
VALVES AND VALVE SPRINGS.............4-34
CYLINDER AND PISTON.........................4-43
CLUTCH....................................................4-50
OIL FILTER ELEMENT, WATER PUMP
AND RIGHT CRANKCASE COVER........4-57
BALANCER..............................................4-64
OIL PUMP.................................................4-67
KICK SHAFT AND SHIFT SHAFT...........4-73
CDI MAGNETO.........................................4-80
ENGINE REMOVAL..................................4-84
CRANKCASE AND CRANKSHAFT.........4-89
TRANSMISSION, SHIFT CAM
AND SHIFT FORK....................................4-98
CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR WHEEL........5-1
FRONT BRAKE AND REAR BRAKE......5-10
FRONT FORK...........................................5-26
HANDLEBAR............................................5-43
STEERING................................................5-49
SWINGARM..............................................5-54
REAR SHOCK ABSORBER.....................5-62

1 - 2
GEN
INFO
MACHINE IDENTIFICATION
EC120001
MACHINE IDENTIFICATION
There are two significant reasons for knowing
the serial number of your machine:
1. When ordering parts, you can give the
number to your Yamaha dealer for positive
identification of the model you own.
2. If your machine is stolen, the authorities will
need the number to search for and identify
your machine.
EC121001
VEHICLE IDENTIFICATION NUMBER
The vehicle identification number 1 is
stamped on the right of the steering head pipe.
EC123001
ENGINE SERIAL NUMBER
The engine serial number 1 is stamped into
the elevated part of the right-side of the
engine.
EC124000
MODEL LABEL
The model label 1 is affixed to the frame
under the rider’s seat. This information will be
needed to order spare parts.

GEN
INFO
1 - 8
SPECIAL TOOLS
YU-33975, 90890-01403 Steering nut wrench
This tool is used when tighten the steering ring nut to
specification.YU-33975 90890-01403
YM-01500, 90890-01500 Cap bolt wrench
This tool is used to loosen or tighten the base valve.YM-01500 90890-01500
YM-01501, 90890-01501 Cap bolt ring wrench
This tool is used to loosen or tighten the damper
assembly.YM-01501 90890-01501
YM-A0948, 90890-01502 Fork seal driver
This tool is used when install the fork oil seal.YM-A0948 90890-01502
YU-3112-C, 90890-03112 Pocket tester
Use this tool to inspect the coil resistance, output
voltage and amperage.YU-3112-C 90890-03112
YM-33277-A, 90890-03141 Timing light
This tool is necessary for checking ignition timing.YM-33277-A 90890-03141
YM-4019, 90890-04019 Valve spring compressor
This tool is needed to remove and install the valve
assemblies.YM-4019 90890-04019
YM-91042, 90890-04086 Clutch holding tool
This tool is used to hold the clutch when removing or
installing the clutch boss securing nut.YM-91042 90890-04086
YM-4111, 90890-04111
YM-4116, 90890-04116Valve guide remover
Intake 4.0 mm (0.16 in)
Exhaust 4.5 mm (0.18 in)
This tool is needed to remove and install the valve
guide.YM-4111
YM-411690890-04111
90890-04116
Part number Tool name/How to use Illustration

GEN
INFO
1 - 18
TORQUE-CHECK POINTS
TORQUE-CHECK POINTS
Frame construction
Combined seat and fuel tank
Exhaust system
Engine mounting
Steering Steering stem to
handlebar
Suspension Front Steering stem to front
fork
Rear For link type
Rear Installation of rear
shock absorber
Rear Installation of swing-
arm
Wheel Installation of wheel Front
Rear
Brake Front
Rear
Fuel system
Lubrication systemFrame to rear frame
Fuel tank to frame
Silencer to rear frame
Frame to engine
Engine bracket to engine
Engine bracket to frame
Steering stem to frame
Steering stem to upper bracket
Upper bracket to handlebar
Front fork to upper bracket
Front fork to lower bracket
Assembly of links
Link to frame
Link to rear shock absorber
Link to swingarm
Rear shock absorber to frame
Tightening of pivot shaft
Tightening of wheel axle
Tightening of axle holder
Tightening of wheel axle
Wheel to rear wheel sprocket
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
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 tank to fuel cock
Tightening of oil hose clamp
NOTE:
Concerning the tightening torque, refer to
“MAINTENANCE SPECIFICATIONS” section
in the CHAPTER 2.

SPEC
2 - 12 CHASSIS
Item Standard Limit
Steering system:
Steering bearing type Taper roller bearing ----
Front suspension: USA, CDN,
AUS, NZ, ZAEUROPE
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 = 4.3 N/mm
(0.438 kg/mm,
24.5 lb/in)← ----
Optional spring Yes← ----
Oil capacity 522 cm
3
(18.4 Imp oz,
17.6 US oz) 527 cm3
(18.6 Imp oz,
17.8 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,
AUS, NZ, ZAEUROPE
Shock absorber travel 131.5 mm
(5.18 in)← ----
Spring free length Approx. 265 mm
(10.43 in)← ----
Fitting length One I.D. mark
257 mm
(10.12 in)One I.D. mark
258 mm
(10.16 in)----
Two I.D. marks
263 mm
(10.35 in)Two I.D. marks
264 mm
(10.39 in)----
Three I.D. marks
254.5 mm
(10.02 in)Three I.D. marks
255.5 mm
(10.06 in)----
One I.D. mark
245.5 ~ 263.5 mm
(9.67 ~ 10.37 in)←----
Two I.D. marks
251.5 ~ 269.5 mm
(9.90 ~ 10.61 in)←----
Three I.D. marks
243.0 ~ 261.0 mm
(9.57 ~ 10.28 in)←----
Spring rate, STD K = 50.0 N/mm
(5.10 kg/mm,
285.6 lb/in)←----
Optional spring Yes← ----
Enclosed gas pressure 1,000 kPa
(10 kg/cm
2,
142 psi)← ----
MAINTENANCE SPECIFICATIONS

SPEC
2 - 14
NOTE:
1. First, tighten the steering ring nut approximately 38 Nm (3.8 m  kg, 27 ft  lb) by using the steer-
ing 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). Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Upper bracket and outer tube M8 × 1.25 4 23 2.3 17
Lower bracket and outer tube M8 × 1.25 4 20 2.0 14
Upper bracket and steering stem M24 × 1.0 1 145 14.5 105
Handlebar upper holder and handlebar lower
holderM8 × 1.25 4 28 2.8 20
Handlebar lower holder and upper bracket M12 × 1.25 2 40 4.0 29
Steering stem and steering ring nut M28 × 1.0 1 Refer to NOTE.
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 7 0.7 5.1
Lower bracket and brake hose guide M6 × 1.0 1 4 0.4 2.9
Front fork protector and brake hose holder M6 × 1.0 2 7 0.7 5.1
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 M5 × 0.8 2 4 0.4 2.9
Clutch lever mounting nut M6 × 1.0 1 4 0.4 2.9
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 23 2.3 17
Front brake caliper and brake hose holder M6 × 1.0 1 10 1.0 7.2
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 23 2.3 17
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 M20 × 1.5 1 125 12.5 90
MAINTENANCE SPECIFICATIONS

2 - 18
SPECCABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1Fuel tank breather hose
2Radiator hose 1
3Cylinder head breather hose
4Radiator hose 4
5Clutch cable
6Throttle position sensor lead
7Fuel hose
8Hot starter cable
9Carburetor breather hose
0Carburetor overflow hose
AConnector coverÈInsert the end of the fuel tank
breather hose into the hole in
the steering stem.
ÉPass the cylinder head
breather hose on the outside of
the radiator hose 1 and on the
inside of the radiator pipe (radi-
ator hose 4).
ÊPass the clutch cable through
the cable guides.
ËPass the clutch cable in front of
the radiator mounting boss.ÌPass the fuel hose between the
hot starter cable and throttle
position sensor lead.
ÍPass the carburetor breather
hoses and overflow hose so
that all there hoses do not con-
tact the rear shock absorber.
ÎInstall the connector cover so
that it does not come in
between the radiator hose 1
and radiator.
B A
99
0
Í
B
A
8
3A2Î
7
Ì
ËÉ
1
È
6
5
4
Ê

3 - 3
INSP
ADJ
MAINTENANCE INTERVALS
FRONT FORK OIL SEAL AND DUST
SEAL
Clean and lube Lithium base grease
PROTECTOR GUIDE
Replace
REAR SHOCK ABSORBER
(After
rain ride)
Inspect and adjust
Lube
Molybdenum disulfide
grease
Replace spring seat Every one year
Retighten
DRIVE CHAIN GUIDE AND ROLLERS
Inspect
SWINGARM
Molybdenum disulfide
grease
Inspect, lube and retighten
RELAY ARM, CONNECTING ROD
Molybdenum disulfide
grease
Inspect, lube and retighten
STEERING HEAD
Inspect free play and retighten
Clean and lube Lithium base grease
Replace bearing
TIRE, WHEELS
Inspect air pressure, wheel run-out,
tire wear and spoke looseness
Retighten sprocket bolt
Inspect bearings
Replace bearings
Lubricate Lithium base grease
THROTTLE, CONTROL CABLE Yamaha cable lube or
SAE 10W-30 motor oil
Inspect dirt and wear on
the throttle cable on the
carburetor side. Check routing and connection
Lubricate
Inspect and clean (throttle cable)
HOT STARTER, CLUTCH LEVER
Inspect free playItemAfter
break-inEvery
race
Every
third
(or
500 km)Every
fifth
(or
1,000 km)As re-
quiredRemarks