2006 YAMAHA TTR125 cylinder

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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)

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ENGCYLINDER HEAD
3. Install:
Timing chain
Camshaft sprocket
4. Install:
Washer
Bolt (camshaft sprocket)
NOTE:
Temporarily tighten the bolt (camshaft sprocket)
at this point. Installation steps:
Turn the crankshaft counterclockwise with
a wrench.
Align the “I” mark a on the rotor with the
stationary pointer b on the crankcase
cover.
Align the match mark c on the camshaft
sprocket with the stationary pointer d on
the cylinder head.
Fit the timing chain 1 onto camshaft
sprocket 2 and install the camshaft
sprocket on the camshaft.
NOTE:
When installing the camshaft sprocket, keep
the timing chain as tense as possible on the
exhaust side.
CAUTION:
Do not turn the crankshaft during instal-
lation of the camshaft. Damage or
improper valve timing will result.
Remove the safety wire from the timing
chain.

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ENGCYLINDER HEAD
5. Install:
Timing chain tensioner
6. Turn:
Crankshaft
Counterclockwise several turns
7. Check:
Rotor “I” mark
Align with the crankcase stationary
pointer.
Camshaft match mark
Align with the cylinder head stationary
pointer.
Out of alignment → Adjust. Installation steps:
While pressing the tensioner rod lightly
with fingers, use a thin screwdriver and
wind the tensioner rod up fully clockwise.
With the rod fully wound, install the gasket
1 and the chain tensioner 2, and tighten
the bolts 3 to the specified torque.
T R..
Bolt (chain tensioner):
10 Nm (1.0 m • kg, 7.2 ft • lb)
Release the screwdriver, check the ten-
sioner rod to come out and tighten the
gasket 4 and the cap bolt 5 to the speci-
fied torque.
T R..
Cap bolt (timing chain tensioner):
8 Nm (0.8 m • kg, 5.8 ft • lb)
8. Tighten:
Bolt 1
NOTE:
Tighten the bolt while holding the rotor nut with
a wrench.
T R..20 Nm (2.0 m · kg, 14 ft · lb)

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ENGCYLINDER HEAD
9. Check:
Valve clearance
Out of specification → Adjust.
Refer to “VALVE CLEARANCE
INSPECTION AND ADJUSTMENT”
section in the CHAPTER 3.
10. Apply:
Engine oil
On camshaft.
11. Install:
Tappet cover 1
Cylinder head side cover 2
T R..18 Nm (1.8 m · kg, 13 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
12. Install:
Timing mark accessing screw 1
Crankshaft end accessing screw 2
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
13. Install:
Spark plug
Engine bracket
T R..13 Nm (1.3 m · kg, 9.4 ft · lb)
T R..40 Nm (4.0 m · kg, 29 ft · lb)

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ENGCAMSHAFT AND ROCKER ARMS
CAMSHAFT AND ROCKER ARMS
Extent of removal:1 Camshaft removal2 Rocker arm removal
Extent of removal Order Part name Q’ty Remarks
CAMSHAFT AND ROCKER
ARMS REMOVAL
Preparation for removal Cylinder head Refer to “CYLINDER HEAD” section.
1 Camshaft bearing holder 1
2 Intake rocker arm shaft 1
Refer to “REMOVAL POINTS”. 3 Exhaust rocker arm shaft 1
4 Camshaft 1
5 Intake rocker arm 1
6 Exhaust rocker arm 1
1
2

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ENGVALVES AND VALVE SPRINGS
VALVES AND VALVE SPRINGS
Extent of removal:1 Valves and valve springs removal
Extent of removal Order Part name Q’ty Remarks
VALVES AND VALVE SPRINGS
REMOVAL
Preparation for removal Cylinder head Refer to “CYLINDER HEAD” section.
Camshaft and rocker arms Refer to “CAMSHAFT AND ROCKER
ARMS” section.
1 Valve cotter 4
Refer to “REMOVAL POINTS”. 2 Valve spring retainer 2
3 Valve spring 2
4 Intake valve 1
5 Exhaust valve 2
6 Valve stem seal 2
7Valve spring seat
2
1

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ENGVALVES AND VALVE SPRINGS
REMOVAL POINTS
Valve
1. Check:
Valve sealing
Leakage at the valve seat → Inspect
the valve face, valve seat and valve
seat width.
Checking steps:
Pour a clean solvent 1 into the intake and
exhaust ports.
Check that the valve seals properly.
There should be no leakage at the valve
seat 2.
2. Remove:
Valve cotters 1
NOTE:
Attach a valve spring compressor 2 between
the valve spring retainer and the cylinder head
to remove the valve cotters.
Valve spring compressor:
YM-4019/90890-04019
3. Remove:
Valve spring retainer 1
Valve spring 2
Valve 3
Valve stem seal 4
Valve spring seat 5
NOTE:
Identify the position of each part very carefully
so that it can be reinstalled in its original place.

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ENGVALVES AND VALVE SPRINGS
INSPECTION
Valve
1. Measure:
Stem-to-guide clearance
Out of specification → Replace the
valve guide. Stem-to-guide clearance =
valve guide inside diameter a –
valve stem diameter b
Clearance (stem to guide):
Intake:
0.010 ~ 0.037 mm
(0.0004 ~ 0.0015 in)
: 0.08 mm (0.0031 in)
Exhaust:
0.025 ~ 0.052 mm
(0.0010 ~ 0.0020 in)
: 0.10 mm (0.0040 in)
2. Replace:
Valve guide
Replacement steps:
NOTE:
To ease guide removal, installation and to
maintain correct fit heat the cylinder head in
an over to 100 ˚C (212 ˚F).
Remove the valve guide using a valve
guide remover 1.
Install the new valve guide using a valve
guide remover and valve guide installer.
After installing the valve guide, bore the
valve guide using a valve guide reamer 2
to obtain proper stem-to-guide clearance.
Valve guide remover:
YM-4097/90890-04097
Valve guide installer:
YM-4098/90890-04098
Valve guide reamer:
YM-04099/90890-04099
NOTE:
After replacing the valve guide reface the
valve seat.