clutch YAMAHA YZ125LC 2007 Manuale duso (in Italian)

CHAPTER 4
ENGINE
SEAT, FUEL TANK AND SIDE
COVERS.....................................................4-1
EXHAUST PIPE AND SILENCER..............4-3
RADIATOR..................................................4-4
CARBURETOR AND REED VALVE...........4-7
CYLINDER HEAD , CYLINDER AND
PISTON.....................................................4-17
CLUTCH AND PRIMARY DRIVEN
GEAR.......................................................4-30
KICK AXLE, SHIFT SHAFT AND
PRIMARY DRIVE GEAR...........................4-37
YPVS GOVERNOR...................................4-45
WATER PUMP..........................................4-48
CDI MAGNETO.........................................4-52
ENGINE REMOVAL..................................4-56
CRANKCASE AND CRANKSHAFT.........4-61
TRANSMISSION, SHIFT CAM AND
SHIFT FORK.............................................4-69
CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR WHEEL........5-1
FRONT BRAKE AND REAR BRAKE.......5-10
FRONT FORK...........................................5-26
HANDLEBAR............................................5-42
STEERING................................................5-50
SWINGARM..............................................5-55
REAR SHOCK ABSORBER.....................5-63
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1-1
GEN
INFO
DESCRIPTION
EC100000
GENERAL INFORMATION
EC110000
DESCRIPTION
1Clutch lever
2“ENGINE STOP” button
3Front brake lever
4Throttle grip
5Radiator cap
6Fuel tank cap
7Kick starter
8Fuel tank
9Radiator
0Coolant drain bolt
qCheck bolt (Transmission oil level)
wRear brake pedal
eValve joint
rFuel cock
tAir cleaner
yDrive chain
uShift pedal
iStarter knob
oFront fork
NOTE:
9The machine you have purchased may differ
slightly from those shown in the following.
9Designs and specifications are subject to
change without notice.
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1-8
GEN
INFO
SPECIAL TOOLS
Part number Tool name / How to use IIIustration
YU-24460-01, 90890-01325Radiator cap testerYU-24460-01 90890-01325
YU-33984, 90890-01352 AdapterYU-33984 90890-01352
These tools are used for checking the cooling
system.
YU-33270-B, 90890-01362Flywheel puller
YU-33270-B 90890-01362
These tool is used to split the crankcase.
YU-33975, 90890-01403 Ring nut wrench
YU-33975 90890-01403
This tool is used when tighten the steering ring nut
to specification.
YM-01500, 90890-01500 Cap bolt wrench
YM-01500 90890-01500
This tool is used to loosen or tighten the base valve.
YM-01501, 90890-01501 Cap bolt ring wrench
YM-01501 90890-01501
This tool is used to loosen or tighten the damper
assembly.
YM-A0948, 90890-01502 Fork seal driver
YM-A0948 90890-01502
This tool is used when install the fork oil seal.
YU-3112-C, 90890-03112 Yamaha pocket tester
YU-3112-C 90890-03112
Use this tool to inspect the coil resistance,
output voltage and amperage.
YM-91042, 90890-04086 Clutch holding tool
YM-91042 90890-04086
This tool is used to hold the clutch when removing
or installing the clutch boss securing nut.
YM-34487 Dynamic spark tester
YM-34487 90890-06754
90890-06754 Ignition checker
This instrument is necessary for checking the igni-
tion system components.
90890-85505 YAMAHA Bond No. 1215
90890-85505 90890-85505
(ThreeBond®No. 1215)
This sealant (Bond) is used for crankcase mating
surface, etc.
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1-9
GEN
INFO
CONTROL FUNCTIONS
EC150000
CONTROL FUNCTIONS
EC151000
“ENGINE STOP” BUTTON
The “ENGINE STOP” button 1is located on the
left handlebar. Continue pushing the “ENGINE
STOP” button till the engine comes to a stop.
EC152000
CLUTCH LEVER
The clutch lever 1is located on the left handle-
bar; it disengages or engages the clutch. Pull
the clutch lever to the handlebar to disengage
the clutch, and release the lever to engage the
clutch. The lever should be pulled rapidly and re-
leased slowly for smooth starts.
EC153000
SHIFT PEDAL
The gear ratios of the constant-mesh 6 speed
transmission are ideally spaced. The gears can
be shifted by using the shift pedal 1on the left
side of the engine.
EC154000
KICK STARTER
Rotate the kick starter 1away from the engine.
Push the starter down lightly with your foot until
the gears engage, then kick smoothly and force-
fully to start the engine. This model has a prima-
ry kick starter so the engine can be started in
any gear if the clutch is disengaged. In normal
practices, however, shift to neutral before start-
ing.
EC155001
THROTTLE GRIP
The throttle grip 1is located on the right han-
dlebar; it accelerates or decelerates the engine.
For acceleration, turn the grip toward you; for
deceleration, turn it away from you.
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2-2
SPECGENERAL SPECIFICATIONS
Carburetor:
Type/Manufacturer TMXχ
38SS/MIKUNI
Spark plug:
Type/Manufacturer BR9EVX/NGK (resistance type)
Gap 0.6~0.7 mm (0.024~0.028 in)
Clutch type: Wet, multiple-disc
Transmission:
Primary reduction system Gear
Primary reduction ratio 64/19 (3.368)
Secondary reduction system Chain drive
Secondary reduction ratio 48/13 (3.692)
Transmission type Constant mesh, 6-speed
Operation Left foot operation
Gear ratio: 1st 31/13 (2.385)
2nd 29/15 (1.933)
3rd 27/17 (1.588)
4th 23/17 (1.353)
5th 24/20 (1.200)
6th 23/21 (1.095)
Chassis:USA, ZA, AUS, NZEUROPE,CDN
Frame type Semi double cradle←
Caster angle 25.5° 25.6°
Trail 105 mm (4.13 in) 107 mm (4.21 in)
T ire:
Type With tube
Size (front) 80/100-21 51M
Size (rear) 100/90-19 57M
T ire 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
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2-3
SPECMAINTENANCE SPECIFICATIONS
Item Standard Limit
Cylinder head:
Combustion chamber capacity 8.4 cm
3…
(0.296 Imp oz, 0.284 US oz)
Warp limit…
0.03 mm (0.0012 in)
Cylinder:
Bore size 54.000~54.014 mm 54.1 mm (2.130 in)
(2.1260~2.1265 in)
Taper limit…
0.05 mm (0.0020 in)
Out of round limit…
0.01 mm (0.0004 in)
Piston:
Piston size/ 53.957~53.972 mm…
(2.1243~2.1249 in)
Measuring point* 17.5 mm (0.69 in)…
Piston clearance 0.040~0.045 mm 0.1 mm (0.004 in)
(0.0016~0.0018 in)
Piston offset 0.5 mm (0.019 in)/EX-side…
Piston pin:
Piston pin outside diameter 14.995~15.000 mm 14.975 mm
(0.5904~0.5906 in) (0.5896 in)
Piston ring:
Sectional sketch Plain…
B=1.0 mm (0.039 in)…
T=2.35 mm (0.093 in)…
End gap (installed) 0.5~0.7 mm (0.020~0.028 in) 1.2 mm (0.047 in)
Side clearance (installed) 0.035~0.070 mm 0.1 mm (0.004 in)
(0.0014~0.0028 in)
Crankshaft:
Crank width “A” 55.90~55.95 mm …
(2.201~2.203 in)
Runout limit “C” 0.03 mm (0.0012 in) 0.05 mm (0.0020 in)
Connecting rod big end
side clearance “D” 0.06~0.64 mm (0.002~0.025 in)…
Small end free play “F” 0.8~1.0 mm (0.031~0.039 in) 2.0 mm (0.08 in)
Clutch:
Friction plate thickness 2.9~3.1 mm (0.114~0.122 in) 2.8 mm (0.110 in)
Quantity 8 …
Clutch plate thickness 1.5~1.7 mm (0.059~0.067 in) …
Quantity 7 …
Warp limit … 0.2 mm (0.008 in)
Clutch spring free length 40.1 mm (1.579 in) 38.1 mm (1.500 in)
Quantity 5 …
Clutch housing thrust clearance 0.15~0.26 mm (0.006~0.010 in) …
Clutch housing radial clearance 0.014~0.046 mm …
(0.0006~0.0018 in)
Clutch release method Inner push, cam push …
EC212000
MAINTENANCE SPECIFICATIONSEC212100
ENGINE
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2-5
SPECMAINTENANCE SPECIFICATIONS
Part to be tightened Thread size Q'tyT ightening torqueNm m•kg ft•lb
Spark plug
M14S×1.25 1 20 2.0 14
Cylinder head (nut) M 8 ×1.25 5 28 2.8 20
(stud) M 8 ×1.25 5 13 1.3 9.4
Cylinder (nut) M 8 ×1.25 4 30 3.0 22
(stud) M10 ×1.25 4 13 1.3 9.4
Power valve:
Cover M 5 ×0.8 4 5 0.5 3.6
Link lever M 4 ×0.7 1 4 0.4 2.9
Holder (power valve) M 5 ×0.8 4 8 0.8 5.8
Push rod M 5 ×0.8 1 5 0.5 3.6
Thrust plate M 5 ×0.8 1 4 0.4 2.9
Governor fork M 4 ×0.7 2 5 0.5 3.6
Housing M 5 ×0.8 3 4 0.4 2.9
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 2 0.2 1.4
Air filter element M 6 ×1.0 1 2 0.2 1.4
Carburetor joint M 6 ×1.0 4 10 1.0 7.2
Carburetor joint clamp M 4 ×0.7 1 2 0.2 1.4
Air filter joint clamp M 4 ×0.7 1 2 0.2 1.4
Air filter case M 6 ×1.0 4 8 0.8 5.8
Air filter guide clamp M 5 ×0.8 1 4 0.4 2.9
Read valve M 3 ×0.5 6 1 0.1 0.7
Throttle cable adjust bolt and locknut M 8 ×1.25 1 7 0.7 5.1
Throttle cable M 6 ×0.75 1 4 0.4 2.9
Crankcase M 6 ×1.0 12 14 1.4 10
Crankcase cover (right) M 6 ×1.0 8 10 1.0 7.2
Crankcase cover (left) M 6 ×1.0 4 5 0.5 3.6
Chain cover M 6 ×1.0 2 5 0.5 3.6
Bearing plate cover M 6 ×1.0 4 10 1.0 7.2
Holder M 6 ×1.0 1 10 1.0 7.2
Oil check bolt M 6 ×1.0 1 10 1.0 7.2
Oil drain bolt M10 ×1.25 1 20 2.0 14
Kick starter M 6 ×1.0 1 10 1.0 7.2
Cluch cover M 6 ×1.0 6 10 1.0 7.2
Primary drive gear M 8 ×1.25 1 48 4.8 35
Clutch boss M16 ×1.0 1 80 8.0 58
Clutch spring M 6 ×1.0 5 10 1.0 7.2
Clutch cable adjust bolt and locknut M 6 ×0.75 1 4 0.4 2.9
Drive sprocket M18 ×1.0 1 75 7.5 54
Shift pedal M 6 ×1.0 1 12 1.2 8.7
Bearing plate cover (shift cam) M 6 ×1.0 2 10 1.0 7.2
Shift guide M 6 ×1.0 2 10 1.0 7.2
Stopper lever M 6 ×1.0 1 10 1.0 7.2
Segment M 8 ×1.25 1 30 3.0 22
 
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2-8
SPECMAINTENANCE SPECIFICATIONS
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 ×1.85/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 111 links+joint …
Chain slack 48~58 mm (1.9~2.3 in) …
Chain length (15 links) … 242.9 mm (9.563 in)
Front disc brake:
Disc outside dia. ×Thickness 250 ×3.0 mm 250 ×2.5 mm
(9.84 ×0.12 in) (9.84 ×0.10 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 245 ×3.5 mm
(9.65 ×0.16 in) (9.65 ×0.14 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. 11.0 mm (0.433 in)…
Caliper cylinder insdie dia. 25.4 mm (1.000 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)…
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2-9
SPECMAINTENANCE SPECIFICATIONS
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).
Part to be tightened Thread size Q'tyT ightening torqueNm m•kg ft•lb
Handle crown and outer tube M 8 ×1.25 4 21 2.1 15
Under bracket and outer tube M 8 ×1.25 4 21 2.1 15
Handle crown and steering shaft M24 ×1.0 1 145 14.5 105
Handlebar holder (upper) M 8 ×1.25 4 28 2.8 20
Handlebar holder (lower) M12 ×1.25 2 40 4.0 29
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
Bleed screw (front fork) and base valve M 5 ×0.8 2 1 0.1 0.7
Front fork and protector M 6 ×1.0 6 7 0.7 5.1
Cable guide (front brake hose) and under bracketM 6 ×1.0 1 4 0.4 2.9
Protector and brake hose holder M 6 ×1.0 2 7 0.7 5.1
Throttle cable cap M 4 ×0.7 2 1 0.1 0.7
Front brake master cylinder and bracket M 6 × 1.0 2 9 0.9 6.5
Brake lever (bolt) M 6 ×1.0 1 6 0.6 4.3
(nut) M 6 ×1.0 1 6 0.6 4.3
Brake lever position locknut M 6 ×1.0 1 5 0.5 3.6
Clutch lever (nut) M 6 ×1.0 1 4 0.4 2.9
Clutch lever holder M 5 ×0.8 2 4 0.4 2.9
Front brake master cylinder cap M 4 ×0.7 2 2 0.2 1.4
Front brake hose union bolt (master cylinder)M10 ×1.25 1 30 3.0 22
Front brake hose union bolt (caliper) M10 ×1.25 1 30 3.0 22
Front brake caliper and front fork M 8 ×1.25 2 23 2.3 17
Front brake caliper and brake hose holder M 6 ×1.0 1 10 1.0 7.2
Grip cap upper and lower M 6 ×1.0 2 4 0.4 2.9
Brake caliper (front and rear) and pad pin plugM10 ×1.0 2 3 0.3 2.2
Brake caliper (front and rear) and pad pin M10 ×1.0 2 18 1.8 13
Brake caliper (front and rear) and bleed screwM 8 ×1.25 2 6 0.6 4.3
Front wheel axle and nut M16 ×1.5 1 105 10.5 75
Front wheel axle holder M 8 ×1.25 4 21 2.1 15
Front brake disc and wheel hub M 6 ×1.0 6 12 1.2 8.7
Rear brake disc and wheel hub M 6 ×1.0 6 14 1.4 10
Footrest bracket and frame M10 ×1.25 4 55 5.5 40
Brake pedal mounting M 8 ×1.25 1 26 2.6 19


 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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2-13
SPECCABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1“ENGINE STOP” button lead
2Throttle cable
3Clutch cable
4Ground lead
5High tension cord
6Clamp
7Air vent hose
8Radiator breather hose
9CDI magneto lead
0YPVS breather hose
qEngine bracket (right)
wEngine bracket (left)
eCrankcase breather hose
rOverflow hose
tConnector coverAPass the clutch cable on the
outside of the throttle cable and
“ENGINE STOP” button lead.
BAlign the throttle cable locating
tape with the cable guide.
CPass the throttle cable, clutch
cable and “ENGINE STOP”
button lead above the radiator
hose.
DInstall the ignition coil, side
core and ground lead together
to the frame. Take care to fas-
ten the ground lead so that its
terminal is within the indicated
range.
EClamp the throttle cable and
high tension cord to the frame.FClamp the clutch cable to the
left engine bracket. Clamp the
clutch cable below the posi-
tioning grommet.
GPass the air vent hose back of
the throttle cable.
HPass the air vent hose, over-
flow hose and crankcase
breather hose between the
frame and connecting rod.
IPass the radiator breather
hose and YPVS breather hose
outside the engine bracket and
inside the down tube. Then
pass the radiator breather
hose inside the YPVS breather
hose.
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