engine YAMAHA WR 250F 2002 Owners Manual

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
Preparation for removal
REAR WHEEL REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING

Support the machine securely so there is no
danger of it falling over.
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”.
10Brake disc
1
2
31
3

FRONT WHEEL AND REAR WHEEL

5 - 11
CHASFRONT BRAKE AND REAR BRAKE
EC5A0000
FRONT BRAKE AND REAR BRAKE
EC5A8000
FRONT BRAKE
Extent of removal:1 Brake hose removal2 Brake caliper removal
3 Brake master cylinder removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalFRONT BRAKE REMOVAL
Hold the machine by placing the
suitable stand under the engine.
Drain the brake fluid.
WARNING
Support the machine securely so there is nodanger of it falling over.
Refer to “REMOVAL POINTS”.
1 Brake hose cover 1
2 Brake hose holder 1
3 Bolt (brake hose holder) 2 Only loosening.
4 Union bolt 2
5 Brake hose 1
6 Pad pin plug 1 Remove when loosening the pad pin.
7 Pad pin 1 Loosen when disassembling the caliper.
8 Brake caliper 1
9 Brake lever 1
10 Brake master cylinder bracket 1
11 Brake master cylinder 1
2
3
1
3
2

5 - 12
CHAS
EC5A8100
REAR BRAKE
Extent of removal:1 Brake caliper removal2 Brake hose removal
3 Brake master cylinder removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalREAR BRAKE REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is nodanger of it falling over.
Rear wheel Refer to “FRONT WHEEL AND REAR
WHEEL” section.
Drain the brake fluid. Refer to “REMOVAL POINTS”.
1 Pad pin plug 1 Remove when loosening the pad pin.
2 Pad pin 1 Loosen when disassembling the caliper.
3 Brake caliper 1
4 Brake hose holder 2
5 Union bolt 2
6 Brake hose 1
7 Brake pedal 1
8 Reservoir tank 1
9 Reservoir hose 1
10Brake master cylinder
1
3
1
321
FRONT BRAKE AND REAR BRAKE

5 - 28
CHASFRONT FORK
EC550000
FRONT FORK
Extent of removal:1 Front fork removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalFRONT FORK REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is no
danger of it falling over.
Front wheel Refer to “FRONT WHEEL AND REAR
WHEEL” section.
Front brake caliper Refer to “FRONT BRAKE AND REAR
BRAKE” section.
Headlight
Handlebar Refer to “HANDLEBAR” section.
1 Protector 1
2 Brake hose holder 2
3 Pinch bolt (upper bracket) 2 Only loosening.
4 Cap bolt 1Loosen when disassembling the front fork.
5 Pinch bolt (lower bracket) 2 Only loosening.
6 Front fork 1
1

5 - 41
CHAS
EC5B0000
HANDLEBAR
Extent of removal:1 Handlebar removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalHANDLEBAR REMOVAL
Headlight
1 Decompression cable 1 Disconnect at the lever side.
2 Decompression lever holder 1
3 Clutch cable 1 Disconnect at the lever side.
4 Clutch lever holder 1
5 Engine stop switch 1
6 Light switch 1
7 Brake master cylinder 1 Refer to “REMOVAL POINTS”.
8 Throttle cable cap 1
9 Throttle cable #2 (pushed) 1 Disconnect at the throttle side.
10 Throttle cable #1 (pulled) 1 Disconnect at the throttle side.
11 Right grip 1 Refer to “REMOVAL POINTS”.
12 Tube guide 1
13 Grip cap cover 1
14 Collar 1
15 Left grip 1 Refer to “REMOVAL POINTS”.
16 Handlebar upper holder 2
17 Handlebar 1
1
HANDLEBAR

5 - 45
CHASHANDLEBAR
8. Install:
Brake master cylinder 1
Brake master cylinder bracket 2
Bolt (brake master cylinder bracket) 3
NOTE:
Install the bracket so that the arrow mark a
faces upward.
First tighten the bolt on the upper side of the
brake master cylinder bracket, and then
tighten the bolt on the lower side.
T R..9 Nm (0.9 m · kg, 6.5 ft · lb)
9. Install:
Light switch 1
T R..2 Nm (0.2 m · kg, 1.4 ft · lb)
10. Install:
Engine stop switch 1
Clutch lever holder 2
Bolt (clutch lever holder) 3
Decompression lever holder 4
Bolt (decompression lever holder) 5
Clamp 6
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)
NOTE:
The engine stop switch, clutch lever holder,
decompression lever holder and clamp
should be installed according to the dimen-
sions shown.
Pass the engine stop switch lead in the mid-
dle of the clutch holder.

5 - 47
CHAS
EC560000
STEERING
Extent of removal:1 Lower bracket removal2 Bearing removal
Extent of removal Order Part name Q’ty Remarks
STEERING 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.
Headlight
Handlebar
Cable guide
Front fenderRefer to “HANDLEBAR” section.
1 Trip meter 1
2 Steering stem nut 1
3 Front fork 2 Refer to “FRONT FORK” section.
4 Upper bracket 1
5 Steering ring nut 1 Use special tool.
Refer to “REMOVAL POINTS”.
6 Lower bracket 1
7Ball race cover
1
2
1
STEERING

5 - 53
CHASSWINGARM
EC570000
SWINGARM
Extent of removal:1 Swingarm removal
Extent of removal Order Part name Q’ty Remarks
SWINGARM 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.
Brake hose holder
Rear brake caliper
Bolt (brake pedal)
Drive chainRefer to “FRONT BRAKE AND REAR
BRAKE” section.
Shift the brake pedal backward.
1 Drive chain case 1
2 Lower chain tensioner 1
3 Bolt (rear shock absorber-relay
arm)1 Hold the swingarm.
4 Bolt (connecting rod) 1
5 Pivot shaft 1
6 Swingarm 1
1

5 - 60
CHASREAR SHOCK ABSORBER
EC580000
REAR SHOCK ABSORBER
Extent of removal:1 Rear shock absorber removal2 Rear shock absorber disassembly
Extent of removal Order Part name Q’ty Remarks
Preparation for removalREAR SHOCK ABSORBER
REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is nodanger of it falling over.
Seat and side covers Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section in the CHAPTER 4.
Silencer Refer to “EXHAUST PIPE AND
SILENCER” section in the CHAPTER 4.
Drain the coolant. Refer to “COOLANT REPLACEMENT”
section in the CHAPTER 3.
Coolant reservoir Refer to “RADIATOR” section in the
CHAPTER 4.
1 Taillight connector 2
2 Band 2
3 Bolt (reservoir tank) 1
4 Clamp (air filter joint) 1 Only loosening.
5 Rear frame 1
6 Bolt (rear shock absorber-relay arm) 1Hold the swingarm.
7 Bolt (rear shock absorber-frame) 1
8 Rear shock absorber 1
12

6 - 1
–+ELEC

ELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC600000
ELECTRICAL
EC610000
ELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC611000
ELECTRICAL COMPONENTS
1
Headlight
2
Voltage regulator
3
Engine stop switch
4
Throttle position sensor
5
Taillight
6
Neutral switch
7
CDI magneto
8
Spark plug
9
Ignition coil
0
Light switch
A
CDI unit
COLOR CODE
B...................... Black
Br .................... Brown
G ..................... Green
Gy ................... Gray
L ...................... Blue
O ..................... Orange
P...................... Pink
R ..................... Red
Sb.................... Sky blue
EC612000
WIRING DIAGRAM
B/L
R/WL/W
LY
L
Y
B
1B L
YYLB
5LB
YBLB
LB
2
6
4 9
8
W
R Br
G PB/YP
B Br
G W
R
O
L Y B/LSbSb
B/L Y O
L
A
Y
Br
Gy
PGR
WB
L YL Y
B B/L
SbW
Sb
WL/W
R/WL/WSbR/WSb
W
O
B
0
7
BGyBGy
Y
BL
B
B
3B/WBB/WG/B
L
B YLB Y

W ..................... White
Y ...................... Yellow
B/L ................... Black/Blue
B/W .................. Black/White
B/Y ................... Black/Yellow
G/B................... Green/Black
L/W .................. Blue/White
R/W .................. Red/White