brake YAMAHA YZ250F 2007 Owner's Manual

3 - 32
INSP
ADJ
FRONT FORK INSPECTION
3. Adjust:
Drive chain slack
Drive chain slack adjustment steps:
Loosen the axle nut 1 and locknuts 2.
Adjust the drive chain slack by turning the
adjusters 3.
To tighten
→ Turn the adjuster
3 coun-
terclockwise.
To loosen
→ Turn the adjuster
3 clock-
wise and push wheel forward.
Turn each adjuster exactly the same
amount to maintain correct axle alignment.
(There are marks a on each side of the
drive chain puller alignment.)
NOTE:
Turn the adjuster so that the drive chain is in
line with the sprocket, as viewed from the
rear.
CAUTION:
Too small drive chain slack will overload
the engine and other vital parts; keep the
slack within the specified limits.
Tighten the axle nut while pushing down
the drive chain.
T R..
Axle nut:
125 Nm (12.5 m  kg, 90 ft  lb)
Tighten the locknuts.
T R..
Locknut:
19 Nm (1.9 m  kg, 12 ft  lb)
EC36C000
FRONT FORK INSPECTION
1. Inspect:
Front fork smooth action
Operate the front brake and stroke the
front fork.
Unsmooth action/oil leakage → Repair or
replace.

3 - 44
INSP
ADJ
LUBRICATION
LUBRICATION
To ensure smooth operation of all compo-
nents, lubricate your machine during setup,
after break-in, and after every race.
1All control cable
2Clutch lever pivot
3Shift pedal pivot
4Footrest pivot
5Throttle-to-handlebar contact
6Drive chain
7Tube guide cable winding portion
8Throttle cable end
9Clutch cable end
0Hot starter cable end
ÈUse Yamaha cable lube or equivalent on these
areas.
ÉUse SAE 10W-30 motor oil or suitable chain
lubricants.
ÊLubricate the following areas with high quality,
lightweight lithium-soap base grease.
CAUTION:
Wipe off any excess grease, and avoid get-
ting grease on the brake discs.
AAA
AAB
CC

4 - 50
ENGCLUTCH
EC4A0000
CLUTCH
Extent of removal:
1 Push rod 1, 2 and push lever shaft removal
2 Push rod 1 disassembly
3 Friction plate and clutch plate removal
4 Primary driven gear removal
Extent of removal Order Part name Q’ty Remarks
CLUTCH REMOVAL
Preparation for removal Drain the engine oil. Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
Brake pedal Refer to “ENGINE REMOVAL” section.
Clutch cable Disconnect at engine side.
1 Clutch cover 1
2 Clutch spring 5
3 Pressure plate 1
4 Push rod 1 1
5 Circlip 1
6 Washer 1
7 Bearing 1
8Ball 1
9 Push rod 2 1
1
4
1
3
2

4 - 57
ENG
OIL FILTER ELEMENT, WATER PUMP AND RIGHT
CRANKCASE COVER
OIL FILTER ELEMENT, WATER PUMP AND RIGHT
CRANKCASE COVER
Extent of removal:
1 Oil filter element removal
2 Water pump removal
3 Right crankcase cover removal
Extent of removal Order Part name Q’ty Remarks
OIL FILTER ELEMENT, WATER
PUMP AND RIGHT CRANK-
CASE COVER REMOVAL
Preparation for removal Drain the engine oil. Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
Drain the coolant. Refer to “COOLANT REPLACEMENT”
section in the CHAPTER 3.
Radiator hose 3 Disconnect at water pump side.
Exhaust pipe Refer to “EXHAUST PIPE AND
SILENCER” section.
Brake pedal Refer to “ENGINE REMOVAL” section.
Right engine guard
1 Oil filter element cover 1
2 Oil filter element 1
13

4 - 85
ENGENGINE REMOVAL
Extent of removal:
1 Engine removal
Extent of removal Order Part name Q’ty Remarks
Ignition coil
Disconnect the CDI magneto lead.
Right engine guard
1 Lower engine guard 1
2 Neutral switch 1
3 Drive chain sprocket cover 1
4 Nut (drive sprocket) 1
Refer to “REMOVAL POINTS”. 5 Lock washer 1
6 Drive sprocket 1
7Clip 1
8 Bolt (brake pedal) 1
9 Brake pedal 1
10 Upper engine bracket 2
11 Lower engine bracket 2
12 Engine mounting bolt 3
13 Pivot shaft 1
Refer to “REMOVAL POINTS”.
14 Engine 1
1

4 - 86
ENGENGINE REMOVAL
EC4M3000
REMOVAL POINTS
EC4F3100
Drive sprocket
1. Remove:
Nut (drive sprocket) 1
Lock washer 2
NOTE:
Straighten the lock washer tab.
Loosen the nut while applying the rear brake.
2. Remove:
Drive sprocket 1
Drive chain 2
NOTE:
Remove the drive sprocket together with the
drive chain.
EC4M3301
Engine removal
1. Remove:
Pivot shaft 1
NOTE:
If the pivot shaft is pulled all the way out, the
swingarm will come loose. If possible, insert a
shaft of similar diameter into the other side of
the swingarm to support it.
2. Remove:
Engine 1
From right side.
NOTE:
Make sure that the couplers, hoses and cables
are disconnected.
1

4 - 87
ENGENGINE REMOVAL
EC4M5000
ASSEMBLY AND INSTALLATION
Engine installation
1. Install:
Engine 1
Install the engine from right side.
Pivot shaft 2
Engine mounting bolt (lower) 3
Lower engine bracket 4
Bolt (lower engine bracket) 5
Patch 6
Engine mounting bolt (front) 7
Upper engine bracket 8
Bolt (upper engine bracket) 9
Engine mounting bolt (upper) 0
Lower engine guard A
Bolt (lower engine guard) B
NOTE:
Apply the molybdenum disulfide grease on
the pivot shaft.
Install the patch with the claw a facing out-
side the chassis.
T R..85 Nm (8.5 m · kg, 61 ft · lb)
T R..53 Nm (5.3 m · kg, 38 ft · lb)
T R..38 Nm (3.8 m · kg, 27 ft · lb)
T R..53 Nm (5.3 m · kg, 38 ft · lb)
T R..34 Nm (3.4 m · kg, 25 ft · lb)
T R..55 Nm (5.5 m · kg, 40 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
Brake pedal
1. Install:
Spring 1
Brake pedal 2
O-ring 3
Bolt (brake pedal) 4
Clip 5
NOTE:
Apply the lithium soap base grease on the bolt,
O-rings and brake pedal bracket.
Drive sprocket
1. Install:
Drive sprocket 1
Drive chain 2
NOTE:
Install the drive sprocket together with the
drive chain.
T R..26 Nm (2.6 m · kg, 19 ft · lb)

4 - 88
ENGENGINE REMOVAL
2. Install:
Lock washer 1
Nut (drive sprocket) 2
NOTE:
Tighten the nut while applying the rear brake.
T R..75 Nm (7.5 m · kg, 54 ft · lb)
3. Bend the lock washer tab to lock the nut.
4. Install:
Drive chain sprocket guide 1
Drive chain sprocket cover 2
Screw (drive chain sprocket cover) 3
T R..8 Nm (0.8 m · kg, 5.8 ft · lb)
Neutral switch and hose guide
1. Install:
Spring 1
Pin 2
O-ring 3
Neutral switch 4
Screw (neutral switch) 5
NOTE:
Apply the lithium soap base grease on the O-
ring.
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)
2. Install:
Hose guide (cylinder head breather hose)
1
Bolt (hose guide) 2
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

5 - 1
CHAS
EC500000
CHASSIS
EC590000
FRONT WHEEL AND REAR WHEEL
EC598000
FRONT WHEEL
FRONT WHEEL AND REAR WHEEL
Extent of removal:
1 Front wheel removal
2 Wheel bearing removal
3 Brake disc removal
Extent of removal Order Part name Q’ty Remarks
FRONT WHEEL REMOVAL
WARNING
Support the machine securely so
there is no danger of it falling over. Preparation for removal Hold the machine by placing the
suitable stand under the engine.
1 Bolt (axle holder) 4 Only loosening.
2 Nut (front wheel axle) 1
3 Front wheel axle 1
4 Front wheel 1
5 Collar 2
6 Oil seal 2
7 Bearing 2 Refer to “REMOVAL POINTS”.
8 Brake disc 1
2
31
3

5 - 2
CHAS
EC598100
REAR WHEEL
Extent of removal:
1 Rear wheel removal
2 Wheel bearing removal
3 Brake disc removal
Extent of removal Order Part name Q’ty Remarks
REAR WHEEL REMOVAL
WARNING
Support the machine securely so
there is no danger of it falling over. Preparation for removal Hold the machine by placing the
suitable stand under the engine.
1 Nut (rear wheel axle) 1
2 Rear wheel axle 1
3 Drive chain puller 2
4 Rear wheel 1 Refer to “REMOVAL POINTS”.
5 Collar 2
6 Rear wheel sprocket 1
7 Oil seal 2
8 Circlip 1
9 Bearing 2 Refer to “REMOVAL POINTS”.
10 Brake disc 1
2
31
3
FRONT WHEEL AND REAR WHEEL