torque YAMAHA YZ250LC 2001 Manuale duso (in Italian)

EC0A0000
CONTENTS
CHAPTER 1
GENERAL INFORMATION
DESCRIPTION............................................1-1
MACHINE IDENTIFICATION......................1-2
IMPORTANT INFORMATION.....................1-3
CHECKING OF CONNECTION..................1-6
SPECIAL TOOLS........................................1-7
CONTROL FUNCTIONS.............................1-9
FUEL AND ENGINE MIXING OIL.............1-12
STARTING AND BREAK-IN.....................1-13
TORQUE-CHECK POINTS.......................1-16
CLEANING AND STORAGE....................1-17
CHAPTER 2
SPECIFICATIONS
GENERAL SPECIFICATIONS....................2-1
MAINTENANCE SPECIFICATIONS...........2-3
GENERAL TORQUE SPECIFICATIONS..2-12
DEFINITION OF UNITS............................2-12
CABLE ROUTING DIAGRAM...................2-13
CHAPTER 3
REGULAR INSPECTION
AND ADJUSTMENTS
MAINTENANCE INTERVALS.....................3-1
PRE-OPERATION INSPECTION AND
MAINTENANCE..........................................3-4
ENGINE.......................................................3-5
CHASSIS...................................................3-17
ELECTRICAL............................................3-38
5MW-9-30-0 7/5/00 2:15 PM Page 18

1-15
STARTING AND BREAK-IN
GEN
INFO
cC
9After the break-in or before each race, you
must check the entire machine for loose fit-
tings and fasteners as per “TORQUE-
CHECK POINTS”.
Tighten all such fasteners as required.
9When any of the following parts have been
replaced, they must be broken in.
CYLINDER AND CRANKSHAFT:
About one hour of break-in operation is
necessary.
PISTON, RING AND GEARS:
These parts require about 30 minutes of
break-in operation at half-throttle or less.
Observe the condition of the engine careful-
ly during operation.
5MW-9-30-1 7/3/00 1:48 PM Page 34

1-16
TORQUE-CHECK POINTS
GEN
INFO
EC1A0012
TORQUE-CHECK POINTS
Frame construction Frame to rear frame
Combined seat and tank Fuel tank to frame
Engine mounting Frame to engine
Steering Steering shaft to Steering shaft to frame
handlebar Steering shaft to handle crown
Handle crown to handlebar
Suspension Front Steering shaft to Front fork to handle crown
front fork Front fork to under bracket
Rear For link type Assembly of links
Link to frame
Link to shock absorber
Link to swingarm
Rear Installation of shock Shock absorber to frame
absorber
Rear Installation of swingarm Tightening of pivot shaft
Wheel Installation of wheel Front Tightening of front axle
Tightening of axle holder
Rear Tightening of rear axle
Wheel to sprocket
Brake Front Caliper to front fork
Brake disc to wheel
Tightening of union bolt
Master cylinder to handlebar
Tightening of air bleeder
Rear Brake disc to wheel
Tightening of union bolt
Master cylinder to frame
Tightening of air bleeder
Fuel system Fuel tank to fuel cock
NOTE:
Concerning the tightening torque, refer to “
MAINTENANCE SPECIFICATIONS” section in
the CHAPTER 2.
5MW-9-30-1 7/3/00 1:49 PM Page 36

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 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 2 4 0.4 2.9
Air filter joint M 5 ´0.8 5 1 0.1 0.7
Reed valve M 3 ´0.5 4 1 0.1 0.7
Exhaust pipe M 6 ´1.0 2 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
Primary drive gear M10 ´1.25 1 55 5.5 40
Clutch boss M20 ´1.0 1 75 7.5 54
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2-6
MAINTENANCE SPECIFICATIONSSPEC
Part to be tightened Thread size Q’tyT ightening torqueNm m•kg ft•lb
Clutch spring M 6 ´1.0 6 10 1.0 7.2
Push lever axle M 5 ´0.8 1 6 0.6 4.3
Drive sprocket M20 ´1.0 1 75 7.5 54
Shift guide M 6 ´1.0 2 10 1.0 7.2
Stopper lever M 6 ´1.0 1 10 1.0 7.2
Torsion spring (shift shaft) stopper bolt M 8 ´1.25 1 22 2.2 16
Segment M 8 ´1.25 1 30 3.0 22
Bearing plate cover (shift cam right) M 6 ´1.0 2 10 1.0 7.2
Shift pedal M 6 ´1.0 1 10 1.0 7.2
5MW-9-30-2 7/3/00 2:20 PM Page 7

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
5MW-9-30-2 7/3/00 2:20 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 ´ –
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 6 ´ 1.0
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
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
2
3
4
2
2
1
1
4
2
4
8
4
4
17
30
30
125
42
3
7
7
34
69
69
69
85
80
80
80
56
53
29
4
19
7
5
10
7
7
7
7
7
7
3
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
0.4
1.9
0.7
0.5
1.0
0.7
0.7
0.7
0.7
0.7
0.7
0.3
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
2.9
13
5.1
3.6
7.2
5.1
5.1
5.1
5.1
5.1
5.1
2.2
5.1
5.1
5.1
NOTE:
- marked portion shall be checked for torque tightening after break-in or before each race.
5MW-9-30-2 7/3/00 2:20 PM Page 11

2-11
MAINTENANCE SPECIFICATIONSSPEC
EC212300
ELECTRICAL
Part to be tightened Thread size Q’tyT ightening torqueNm m•kg ft•lb
Stator M 6 ´1.0 3 8 0.8 5.8
Rotor M10 ´1.25 1 41 4.1 30
Ignition coil M 6 ´1.0 2 7 0.7 5.1
Item Standard Limit
Ignition system:
Ignition timing (B.T.D.C.) 0.18 mm (0.007 in)…
Advancer type Electrical…
CDI:
Magneto-model/Manufacturer F5CU10/YAMAHA…
Source coil 1 resistance (color) 720~1,080 ½at 20°C (68°F)…
(Black-Black/Red)
Source coil 2 resistance (color) 44~66 ½at 20°C (68°F)…
(Green/Blue-Green/White)
Pickup coil resistance (color) 248~372 ½at 20°C (68°F)…
(White/Blue-White/Red)
CDI unit-model/Manufacturer 5HC-00/YAMAHA…
Ignition coil:
Model/Manufacturer 5BE-00/YAMAHA…
Minimum spark gap 6 mm (0.24 in)…
Primary winding resistance 0.20~0.30 ½at 20°C (68°F)…
Secondary winding resistance 9.5~14.3 k½at 20°C (68°F)…
5MW-9-30-2 7/3/00 2:20 PM Page 12

2-12
GENERAL TORQUE SPECIFICATIONS/
DEFINITION OF UNITS
SPEC
This chart specifies torque for standard faste-
ners with standard I.S.O. pitch threads. Torque
specifications for special components or assem-
blies are included in the applicable sections of
this book. To avoid warpage, tighten multi-faste-
ner assemblies in a crisscross fashion, in pro-
gressive stages, until full torque is reached.
Unless otherwise specified, torque specifications
call for clean, dry threads. Components should
be at room temperature.
A: Distance across flats
B: Outside thread diameter
EC230000
DEFINITION OF UNITS
EC220001
GENERAL TORQUE SPECIFICATIONS
ABTORQUE SPECIFICATION
(Nut) (Bolt)
Nm m•kg ft•lb
10 mm 6 mm 6 0.6 4.3
12 mm 8 mm 15 1.5 11
14 mm 10 mm 30 3.0 22
17 mm 12 mm 55 5.5 40
19 mm 14 mm 85 8.5 61
22 mm 16 mm 130 13 94
Unit Read Definition Measure
mm milimeter 10-
3meter Length
cm centimeter 10-2meter Length
kg kilogram 103gram Weight
N Newton 1 kg ´m/sec2Force
Nm Newton meter N ´m Torque
m•kg Meter kilogrma m ´kg Torque
Pa Pascal N/m2Pressure
N/mm Newton per millimeter N/mm Spring rate
L Liter — Volume or capacity
cm3Cubic centimeter — Volume or capacity
r/min Revolution per minute — Engine speed
5MW-9-30-2 7/3/00 2:20 PM Page 13

3-35
STEERING HEAD INSPECTION AND ADJUSTMENT
INSP
ADJ
2. Inspect:
9Bearing free play
Exist play ÕReplace.
EC36U013
STEERING HEAD INSPECTION AND
ADJUSTMENT
1. Elevate the front wheel by placing a suitable
stand under the engine.
2. Check:
9Steering shaft
Grasp the bottom of the forks and gently
rock the fork assembly back and forth.
Free play ÕAdjust steering head.
3. Check:
9Steering smooth action
Turn the handlebar lock to lock.
Unsmooth action ÕAdjust steering ring
nut.
4. Adjust:
9Steering ring nut
Steering ring nut adjustment steps:
9Remove the number plate.
9Remove the handlebar and handle crown.
9Loosen the ring nut 1using the ring nut
wrench 2.
9Tighten the ring nut 3using ring nut wrench
4.
NOTE:
Set the torque wrench to the ring nut wrench
so that they form a right angle.
Ring nut wrench:
YU-33975/90890-01403
5MW-9-30-3B 7/3/00 3:28 PM Page 38