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4 - 16
ENGCYLINDER HEAD
Warpage limit:
0.03 mm (0.0012 in)
If the warpage is out of specification,
resurface the cylinder head.
Place #400 ~ 600 grit wet sandpaper on
the surface plate, and re-surface the head
using a figure-eight sanding pattern.
NOTE:
Rotate the cylinder head several times to
avoid removing too much material from one
side.
ASSEMBLY AND INSTALLATION
Cylinder head
1. Install:
Dowel pin 1
Gasket 2 New
2. Install:
Cylinder head
Copper washer
Bolt (cylinder head)
NOTE:
Apply Quick gasket® (YAMAHA Bond
No.1215) on end of the cylinder head bolts
(M6), as shown.
Apply the engine oil on the contact surfaces of
the bolts (cylinder head) and copper washers.
Follow the numerical order shown in the illus-
tration. Tighten the bolts in two stages.
Quick gasket®:
ACC-QUICK-GS-KT
YAMAHA Bond No.1215:
90890-85505
T R..M8 22 Nm (2.2 m · kg, 16 ft · lb)
M6 10 Nm (1.0 m · kg, 7.2 ft · lb)
Page 352 of 610
4 - 47
ENGCLUTCH AND PRIMARY DRIVEN GEAR
5. Install:
Ball
NOTE:
Apply the engine oil on the ball.
6. Install:
Push rod 1 1
Push plate 2
Washer 3
Nut (push rod 1) 4
7. Install:
Pressure plate 1
Clutch spring 2
Bolt (clutch spring) 3
NOTE:
Align the arrow mark a on the pressure
plate with the punched mark b on the clutch
boss.
Tighten the bolts in stage, using a crisscross
pattern.
T R..6 Nm (0.6 m · kg, 4.3 ft · lb)
8. Check:
Push lever position
Push the push lever assembly in the
arrow direction and make sure that the
mach mark are aligned → adjust.
aMatch mark on the push lever assembly
bMatch mark on the crankcase
Page 354 of 610

4 - 48
ENGCLUTCH AND PRIMARY DRIVEN GEAR
9. Adjust:
Push lever position
10. Install:
Dowel pins
Gasket (right crankcase cover)
Right crankcase cover
Negative battery lead
(TT-R125E/TT-R125LWE) 1
Lead holder
(TT-R125E/TT-R125LWE) 2
Bolts (right crankcase cover)
NOTE:
Apply Quick gasket® (YAMAHA Bond
No.1215) to end of the right crankcase cover
bolts, as shown.
Tighten the bolts in stages, using a criss-
cross pattern. Adjustment steps:
Loosen the locknut 1.
Turn the push rod 1 2 clockwise or coun-
terclockwise to match alignment marks.
Hold the push rod 1 to prevent it from
moving and tighten the locknut to specifi-
cation.
Tighten the locknut 1.
T R..
Locknut:
8 Nm (0.8 m • kg, 5.8 ft • lb)
Quick gasket®:
ACC-QUICK-GS-KT
YAMAHA Bond No.1215:
90890-85505
New
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
11. Install:
Kickstarter crank 1
Nut (kickstarter crank) 2
NOTE:
Install the kickstarter crank so that there is 5 ~
10 mm (0.2 ~ 0.4 in) a between the kickstarter
crank and the right crankcase cover.
T R..50 Nm (5.0 m · kg, 36 ft · lb)
Page 378 of 610
4 - 60
ENG
2. Install:
Woodruff key 1
Rotor 2
NOTE:
Clean the tapered portions of the crankshaft
and rotor.
When installing the woodruff key, make sure
that its flat surface a is in parallel with the
crankshaft center line b.
When installing the rotor, align the keyway of
the rotor with the woodruff key.
3. Install:
Plain washer 1
Nut (rotor) 2
Use the sheave holder 3.
Sheave holder:
YS-1880-A/90890-01701
T R..80 Nm (8.0 m · kg, 58 ft · lb)
4. Install:
Dowel pin
Gasket
Left crankcase cover
Bolt (left crankcase cover)
NOTE:
Tighten the screws in stage, using a crisscross
pattern.
New
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
5. Connect:
CDI magneto lead
Refer to “CABLE ROUTING DIAGRAM”
section in the CHAPTER 2.
CDI MAGNETO (TT-R125/TT-R125LW)
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ENGCRANKCASE, CRANKSHAFT AND BALANCER
3. Tighten:
Lead guide 1
Clutch cable holder 2
Bolt (crankcase) [45 mm (1.8 in)] 3
Bolt (crankcase) [55 mm (2.2 in)] 4
Bolt (crankcase) [30 mm (1.2 in)] 5
NOTE:
Apply Quick gasket® (YAMAHA Bond
No.1215) on end of the crankcase bolts
[45 mm (1.8 in)] 3, as shown.
Tighten the crankcase bolts in stage, using a
crisscross pattern.
Quick gasket®:
ACC-QUICK-GS-KT
YAMAHA Bond No.1215:
90890-85505
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
4. Check:
Crankshaft and transmission operation
Unsmooth operation → Repair.
5. Install:
Timing chain 1
Intake timing chain guide 2
Bolt (intake timing chain guide)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)LT
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5 - 11
CHASFRONT WHEEL (TT-R125LW/TT-R125LWE)
2. Install:
Brake disc 1
Bolt (brake disc) 2
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)LT
3. Install:
Collar 1
NOTE:
Apply the lithium soap base grease on the oil
seal lips.
Install the longer collar on the brake disc 2
side.
4. Install:
Front wheel
NOTE:
Install the brake disc 1 between the brake
pads 2 correctly.
5. Install:
Wheel axle 1
6. Install:
Washer 1
Axle nut 2
T R..45 Nm (4.5 m · kg, 32 ft · lb)