2004 YAMAHA TTR125 oil

4 - 19
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)

4 - 22
ENGCAMSHAFT AND ROCKER ARMS
Rocker arms and rocker arm shafts
1. Inspect:
Cam lobe contact surface a
Adjuster surface 1
Wear/pitting/scratches/blue discolora-
tion → Replace.
Measurement steps:
Measure the inside diameter a of the
rocker arm holes.
Out of specification → Replace.
Inside diameter (rocker arm):
10.000 ~ 10.015 mm
(0.3937 ~ 0.3943 in)
: 10.03 mm (0.3949 in)
Measure the outside diameter b of the
rocker arm shafts.
Out of specification → Replace.
Outside diameter
(rocker arm shaft):
9.981 ~ 9.991 mm
(0.3930 ~ 0.3933 in)
: 9.95 mm (0.3917 in)
ASSEMBLY AND INSTALLATION
1. Apply:
Molybdenum disulfide oil
(onto the camshaft cam lobe and rocker
arm hole)
Engine oil
(onto the camshaft bearing)
2. Install:
Rocker arms
Camshaft 1
3. Apply:
Engine oil
(onto the rocker arm shaft)
4. Install:
Rocker arm shaft

4 - 27
ENGVALVES AND VALVE SPRINGS
3. Inspect:
Valve face
Pitting/wear → Grind the face.
Valve stem end
Mushroom shape or diameter larger
than the body of the stem → Replace.
4. Measure:
Margin thickness a
Out of specification → Replace.
5. Measure:
Runout (valve stem)
Out of specification → Replace.
NOTE:
When installing a new valve always replace
the guide.
If the valve is removed or replaced always
replace the oil seal.
Margin thickness:
Intake:
0.4 ~ 0.8 mm
(0.0157 ~ 0.0315 in)
Exhaust:
0.8 ~ 1.2 mm
(0.0315 ~ 0.0472 in)
Runout limit:
0.01 mm (0.0004 in)
6. Eliminate:
Carbon deposits
(from the valve face and valve seat)
7. Inspect:
Valve seats
Pitting/wear → Reface the valve seat.

4 - 28
ENGVALVES AND VALVE SPRINGS
8. Measure:
Valve seat width a
Out of specification → Reface the valve
seat.
Valve seat width:
Intake:
0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in)
: 1.6 mm (0.0630 in)
Exhaust:
0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in)
: 1.6 mm (0.0630 in)
Measurement steps:
Apply Mechanic’s blueing dye (Dykem) b
to the valve face.
Install the valve into the cylinder head.
Press the valve through the valve guide
and onto the valve seat to make a clear
pattern.
Measure the valve seat width. Where the
valve seat and valve face made contact,
blueing will have been removed.
If the valve seat is too wide, too narrow, or
the seat is not centered, the valve seat
must be refaced.
9. Lap:
Valve face
Valve seat
NOTE:
After refacing the valve seat or replacing the
valve and valve guide, the valve seat and
valve face should be lapped.
Lapping steps:
Apply a coarse lapping compound to the
valve face.
CAUTION:
Do not let the compound enter the gap
between the valve stem and the valve
guide.
Apply molybdenum disulfide oil to the
valve stem.

4 - 30
ENGVALVES AND VALVE SPRINGS
2. Measure:
Compressed spring force a
Out of specification → Replace.
bInstalled length
3. Measure:
Spring tilt a
Out of specification → Replace.
Compressed spring force:
Intake:
14.0 ~ 16.1 kg at 25.6 mm
(30.86 ~ 35.49 lb at 1.01 in)
Exhaust:
14.0 ~ 16.1 kg at 25.6 mm
(30.86 ~ 35.49 lb at 1.01 in)
Spring tilt limit:
Intake:
2.5˚/1.4 mm (0.06 in)
Exhaust:
2.5˚/1.4 mm (0.06 in)
ASSEMBLY AND INSTALLATION
Valve
1. Apply:
Molybdenum disulfide oil
(onto the valve stem and valve stem
seal)
2. Install:
Valve spring seats 1
Valve stem seals 2
Valves 3
Valve springs 4
Valve spring retainers 5
NOTE:
Make sure that each valve is installed in its
original place.
Install the valve springs with the larger pitch
a facing upwards.
bSmaller pitch
New

4 - 36
ENGCYLINDER AND PISTON
Piston ring
1. Measure:
Ring side clearance
Use a feeler gauge.
Out of specification → Replace the pis-
ton and rings as a set.
NOTE:
Clean carbon from the piston ring grooves and
rings before measuring the side clearance.
Side clearance:
Standard
Top
ring0.035 ~ 0.090 mm
(0.0014 ~ 0.0035 in)0.12 mm
(0.0047 in)
2nd
ring0.020 ~ 0.060 mm
(0.0008 ~ 0.0024 in)0.12 mm
(0.0047 in)
2. Position:
Piston ring
(in cylinder)
NOTE:
Insert a ring into the cylinder and push it
approximately 40 mm (1.57 in) into the cylin-
der. Push the ring with the piston crown so that
the ring will be at a right angle to the cylinder
bore.
a40 mm (1.57 in)
3. Measure:
Ring end gap
Out of specification → Replace.
NOTE:
You cannot measure the end gap on the
expander spacer of the oil control ring. If the oil
control ring rails show excessive gap, replace
all three rings.
End gap:
Standard
Top
ring0.15 ~ 0.30 mm
(0.006 ~ 0.012 in)0.4 mm
(0.016 in)
2nd
ring0.30 ~ 0.45 mm
(0.012 ~ 0.018 in)0.55 mm
(0.022 in)
Oil ring0.20 ~ 0.70 mm
(0.01 ~ 0.03 in)—

4 - 38
ENGCYLINDER AND PISTON
ASSEMBLY AND INSTALLATION
Piston ring and piston
1. Install:
Piston rings
(onto the piston)
NOTE:
Be sure to install the 2nd piston ring so that
the manufacturer’s mark or number are
located on the upper side of the ring.
Lubricate the piston and piston rings liberally
with engine oil.
2. Position:
Top ring
2nd ring
Oil ring
Offset the piston ring end gaps as
shown.
a: Top ring end
b: 2nd ring end
c: Oil ring end (upper)
d: Oil ring end (lower)
3. Install:
Piston 1
Piston pin 2
Piston pin clips 3
NOTE:
Apply engine oil onto the piston pin, piston
rings and piston.
Be sure that the arrow mark a on the piston
points to the exhaust side of the engine.
Before installing the piston pin clip, cover the
crankcase with a clean rag to prevent the
piston pin clip from falling into the crankcase.
When removing the piston pin clip, pop it out
using the small opening b.
4. Lubricate:
Piston
Piston rings
Inside of cylinder
NOTE:
Apply a liberal coating of engine oil.
New

4 - 40
ENGCLUTCH AND PRIMARY DRIVEN GEAR
EC490000
CLUTCH AND PRIMARY DRIVEN GEAR
EC498000
CLUTCH PLATE AND FRICTION PLATE
Extent of removal:1 Clutch plate and friction plate removal
Extent of removal Order Part name Q’ty Remarks
CLUCTH PLATE AND FRIC-
TION PLATE REMOVAL
Preparation for removal Drain the engine oil. Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
Engine skidplate Refer to “ENGINE REMOVAL” section.
Starter motor for the TT-R125E/
TT-R125LWE1 Refer to “ELECTRIC STARTING SYS-
TEM” section in the CHAPTER 6 for the
TT-R125E/TT-R125LWE.
1 Kickstarter crank 1
2 Starter motor lead holder 2 TT-R125E/TT-R125LWE
3 Negative battery lead 1 TT-R125E/TT-R125LWE
4 Gasket 1
5 Dowel pin 2
6 Pressure plate 1
7 Ball 1
8 Friction plate 5
9 Clutch plate 4
10 Nut/washer 1/1
11 Push rod 1 1
12Push plate
1
1