2002 YAMAHA YZ250LC wheel size

2-2
GENERAL SPECIFICATIONSSPEC
Carburetor:
Type/Manufacturer PWK38S/KEIHIN
Spark plug:
Type/Manufacturer BR8EG/NGK
Gap 0.5~0.6 mm (0.020~0.024 in)
Clutch type: Wet, multiple-disc
Transmission: USA, ZA, AUS, NZ EUROPE, CDN
Primary reduction system Gear←
Primary reduction ratio 63/21 (3.000)←
Secondary reduction system Chain drive←
Secondary reduction ratio 50/14 (3.571) 49/14 (3.500)
Transmission type Constant mesh,←
5-speed
Operation Left foot operation←
Gear ratio: 1st 27/14 (1.929)←
2nd 25/16 (1.563)←
3rd 23/18 (1.278)←
4th 24/22 (1.091)←
5th 20/21 (0.952)←
Chassis:USA, ZA, AUS, NZEUROPE, CDN
Frame type Semi double cradle←
Caster angle 27.0° 26.8°
Trail 118 mm (4.65 in) 114 mm (4.49 in)
Tire:
Type With tube
Size (front) 80/100-21 51M
Size (rear) 110/90-19 62M
Tire pressure (front and rear) 100 kPa (1.0 kgf/cm2, 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:
Front wheel travel 300 mm (11.8 in)
Rear wheel travel 315 mm (12.4 in)
Electrical:
Ignition system CDI magneto
2
5NX-9-30-2 6/7/01 1:57 PM Page 3

2-5
MAINTENANCE SPECIFICATIONSSPEC
Part to be tightened Thread size Q’tyT ightening torqueNm m•kg ft•lb
Spark plug M14 ×1.25 1 20 2.0 14
Cylinder head (nut) M 8 ×1.25 6 25 2.5 18
(stud) M 8 ×1.25 6 13 1.3 9.4
Cylinder (nut) M10 ×1.25 4 35 3.5 25
(stud) M10 ×1.25 4 13 1.3 9.4
Power valve :
Holder M 5 ×0.8 2 6 0.6 4.3
Link rod M 5 ×0.8 2 6 0.6 4.3
Push rod M 5 ×0.8 1 5 0.5 3.6
Thrust plate M 5 ×0.8 1 6 0.6 4.3
Side holder M 5 ×0.8 4 4 0.4 2.9
Link lever M 4 ×0.7 1 4 0.4 2.9
Pulley M 4 ×0.7 2 4 0.4 2.9
Cover M 5 ×0.8 4 4 0.4 2.9
Governor fork M 4 ×0.7 2 5 0.5 3.6
Housing M 5 ×0.8 4 5 0.5 3.6
Impeller M 8 ×1.25 1 14 1.4 10
Water pump housing cover M 6 ×1.0 4 10 1.0 7.2
Coolant drain bolt M 6 ×1.0 1 10 1.0 7.2
Radiator M 6 ×1.0 6 10 1.0 7.2
Radiator panel M 6 ×1.0 2 10 1.0 7.2
Radiator hose clamp M 6 ×1.0 8 1 0.1 0.7
Air filter element M 6 ×1.0 1 2 0.2 1.4
Carburetor joint M 6 ×1.0 5 10 1.0 7.2
Air filter case M 6 ×1.0 4 8 0.8 5.8
Air filter guide clamp M 5 ×0.8 1 1 0.1 0.7
Reed valve M 3 ×0.5 4 1 0.1 0.7
Exhaust pipe (front) M 6 ×1.0 1 14 1.4 10
Exhaust pipe (rear) M 6 ×1.0 1 12 1.2 8.7
Exhaust pipe stay (front) M 8 ×1.25 1 25 2.5 18
Exhaust pipe stay (rear) M 6 ×1.0 1 12 1.2 8.7
Silencer (front) M 6 ×1.0 1 12 1.2 8.7
Silencer (rear) M 6 ×1.0 1 7 0.7 5.1
Fiber (silencer) M 6 ×1.0 2 10 1.0 7.2
Crankcase M 6 ×1.0 11 14 1.4 10
Crankcase cover (left) M 6 ×1.0 5 8 0.8 5.8
Chain cover M 6 ×1.0 2 8 0.8 5.8
Crankcase cover (right) M 6 ×1.0 9 10 1.0 7.2
Bearing plate cover (drive axle left) M 6 ×1.0 2 10 1.0 7.2
Bearing plate cover (main axle right) M 6 ×1.0 2 10 1.0 7.2
Holder M 6 ×1.0 2 10 1.0 7.2
Oil drain bolt M12 ×1.5 1 20 2.0 14
Oil check bolt M 6 ×1.0 1 10 1.0 7.2
Kick starter M 8 ×1.25 1 30 3.0 22
Ratchet wheel stopper M 6 ×1.0 2 10 1.0 7.2
Clutch cover M 6 ×1.0 6 10 1.0 7.2
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2-8
MAINTENANCE SPECIFICATIONSSPEC
Item Standard Limit
Wheel:
Front wheel type Spoke wheel…
Rear wheel type Spoke wheel…
Front rim size/Material 21 ×1.60/Aluminum…
Rear rim size/Material 19 ×2.15/Aluminum…
Rim runout limit:
Radial…
2.0 mm (0.08 in)
Lateral…
2.0 mm (0.08 in)
Drive chain
Type/Manufacturer DID520DMA2 SDH/DAIDO…
Number of links 113 links + joint…
Chain slack 40~50 mm (1.6~2.0 in)…
Chain length (10 links)…
152.5 mm (6.004 in)
Front disc brake:
Disc outside dia. ×Thickness 250 ×3.0 mm (9.84 ×0.12 in)…
Pad thickness 4.4 mm (0.17 in) 1.0 mm (0.04 in)
Master cylinder inside dia. 11.0 mm (0.433 in)…
Caliper cylinder inside dia. 27.0 mm (1.063 in) ×2…
Brake fluid type DOT #4…
Rear disc brake:
Disc outside dia. ×Thickness 245 ×4.0 mm (9.65 ×0.16 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. 12.7 mm (0.500 in)…
Caliper cylinder insdie dia. 27.0 mm (1.063 in)…
Brake fluid type DOT #4…
Brake lever & brake pedal:
Brake lever position 95 mm (3.74 in)…
Brake pedal height Zero mm (Zero in)…
(vertical height above footrest top)
Clutch lever free play (lever end) 8~13 mm (0.31~0.51 in)…
Throttle grip free play 3~5 mm (0.12~0.20 in)…
5NX-9-30-2 6/7/01 1:57 PM Page 9

2-9
MAINTENANCE SPECIFICATIONSSPEC
17
14
105
20
22
40
21
0.7
7.2
7.2
11
5.1
0.7
2.9
1.4
2.9
6.5
1.4
4.3
4.3
3.6
2.9
22
22
17
2.2
13
4.3
75
17
8.7
10
19
7.2M 8 × 1.25
M 8 × 1.25
M24 × 1.0
M 8 × 1.25
M28 × 1.0
M48 × 1.0
M30 × 1.0
M12 × 1.25
M 5 × 0.8
M 6 × 1.0
M 6 × 1.0
M 8 × 1.25
M 6 × 1.0
M 4 × 0.7
M 6 × 1.0
M 6 × 1.0
M 5 × 0.8
M 6 × 1.0
M 4 × 0.7
M 6 × 1.0
M 6 × 1.0
M 6 × 1.0
M 5 × 0.8
M10 × 1.25
M10 × 1.25
M 8 × 1.25
M10 × 1.0
M10 × 1.0
M 8 × 1.25
M16 × 1.5
M 8 × 1.25
M 6 × 1.0
M 6 × 1.0
M 8 × 1.25
M 6 × 1.0 Handle crown and outer tube
Under bracket and outer tube
Handle crown and steering shaft
Handlebar holder (upper)
Steering ring nut
Front fork and cap bolt
Front fork and base valve
Cap bolt and damper rod (front fork)
Bleed screw (front fork) and cap bolt
Front fork and protector
Front fork and brake hose holder
Front fork and hose cover
Front fork and hose cover
Throttle cable cap
Grip cap upper and lower
Clutch lever (bolt)
Clutch lever holder
Front brake master cylinder and bracket
Front brake master cylinder cap
Brake lever mounting (bolt)
Brake lever mounting (nut)
Brake lever position locknut
Cable guide (front brake hose) and guide stay
Front brake hose union bolt (master cylinder)
Front brake hose union bolt (caliper)
Front brake caliper and front fork
Brake caliper (front and rear) and pad pin plug
Brake caliper (front and rear) and pad pin
Brake caliper (front and rear) and bleed screw
Front wheel axle and nut
Front wheel axle holder
Front brake disc and wheel hub
Rear brake disc and wheel hub
Brake pedal mounting
Rear brake master cylinder and framePart to be tightened Thread size Q’tyTightening torque
Nm m•kg ft•lb
4
4
1
4
1
2
2
2
2
6
2
1
1
2
2
1
2
2
2
1
1
1
1
1
1
2
1
1
1
1
4
6
6
1
223
20
145
28
30
55
29
1
10
10
16
7
1
4
2
4
9
2
6
6
5
4
30
30
23
3
18
6
105
23
12
14
26
102.3
2.0
14.5
2.8
3.0
5.5
2.9
0.1
1.0
1.0
1.6
0.7
0.1
0.4
0.2
0.4
0.9
0.2
0.6
0.6
0.5
0.4
3.0
3.0
2.3
0.3
1.8
0.6
10.5
2.3
1.2
1.4
2.6
1.0
NOTE:
1. First, tighten the ring nut approximately 38 Nm (3.8 m•kg, 27 ft•lb) by using the ring nut wrench,
then loosen the ring nut one turn.
2. Retighten the ring nut 7 Nm (0.7 m•kg, 5.1 ft•lb).
Refer to NOTE
5NX-9-30-2 6/7/01 1:57 PM Page 10

2-10
MAINTENANCE SPECIFICATIONSSPEC
M 6 × 1.0
M10 × 1.25
M10 × 1.25
M20 × 1.5
M 8 × 1.25
–
M 6 × 1.0
M 6 × 1.0
M 8 × 1.25
M10 × 1.25
M10 × 1.25
M10 × 1.25
M16 × 1.5
M14 × 1.5
M14 × 1.5
M14 × 1.5
M10 × 1.25
M10 × 1.25
M 8 × 1.25
M 5 ×0.8
M 4 ×0.7
M 8 × 1.25
M 6 × 1.0
M 5 ×0.8
M 6 × 1.0
M 6 × 1.0
M 6 × 1.0
M 6 × 1.0
M 6 × 1.0
M 8 × 1.25
M 6 × 1.0
M 6 × 1.0
M 6 × 1.0
M 6 × 1.0
M 6 × 1.0 Rear brake reservoir tank and frame
Rear brake hose union bolt (caliper)
Rear brake hose union bolt (master cylinder)
Rear wheel axle and nut
Driven sprocket and wheel hub
Nipple (spoke)
Disc cover and rear brake caliper
Protector and rear brake caliper
Engine mounting:
Engine bracket and frame
Engine and frame (front)
Engine and frame (upper)
Engine and frame (lower)
Pivot shaft and nut
Relay arm and swingarm
Relay arm and connecting rod
Connecting rod and frame
Rear shock absorber and frame
Rear shock absorber and relay arm
Rear frame and frame
Swingarm and brake hose holder
Swingarm and patch
Drive chain tensioner mounting
Chain support and swingarm
Seal guard and swingarm
Fuel tank mounting
Fuel tank and fuel cock
Fuel tank and seat set bracket
Fuel tank and hooking screw (fitting band)
Fuel tank and fuel tank bracket
Seat mounting
Side cover mounting
Air scoop mounting
Front fender mounting
Rear fender mounting
Number platePart to be tightened Thread size Q’tyTightening torque
Nm m•kg ft•lb
1
1
1
1
6
72
2
2
2
1
1
1
1
1
1
1
1
1
3
4
4
2
3
4
2
2
1
1
4
2
2
6
4
4
17
30
30
125
42
3
7
7
34
69
69
69
85
80
80
80
56
53
29
1
2
19
7
6
10
7
7
7
7
19
7
4
7
7
70.7
3.0
3.0
12.5
4.2
0.3
0.7
0.7
3.4
6.9
6.9
6.9
8.5
8.0
8.0
8.0
5.6
5.3
2.9
0.1
0.2
1.9
0.7
0.6
1.0
0.7
0.7
0.7
0.7
1.9
0.7
0.4
0.7
0.7
0.75.1
22
22
90
30
2.2
5.1
5.1
24
50
50
50
61
58
58
58
40
38
21
0.7
1.4
13
5.1
4.3
7.2
5.1
5.1
5.1
5.1
13
5.1
2.9
5.1
5.1
5.1
NOTE:
- marked portion shall be checked for torque tightening after break-in or before each race.
5NX-9-30-2 6/7/01 1:57 PM Page 11