2004 YAMAHA TTR125 engine

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 - 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

4 - 45
ENGCLUTCH AND PRIMARY DRIVEN GEAR
Push rod
1. Inspect:
Push rod 1 1
Ball 2
Wear/damage/bend → Replace.
Primary drive gear
1. Inspect:
Primary drive gear
Wear/damage → Replace.
EC495000
ASSEMBLY AND INSTALLATION
Push lever
1. Install:
Push lever 1
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
Apply the engine oil on the push lever.
Primary drive gear
1. Install:
Straight key
Primary drive gear 1
Washer 2
Nut (primary drive gear) 3
Primary driven gear 4
NOTE:
Install the primary drive gear with the stamp
a facing out.
Place a folded rag or aluminum plate 5
between the teeth of the primary drive gear
and primary driven gear.
T R..70 Nm (7.0 m · kg, 50 ft · lb)

4 - 46
ENGCLUTCH AND PRIMARY DRIVEN GEAR
Clutch
1. Install:
Conical spring washer 1
Thrust plate 2
Primary driven gear 3
Thrust plate 4
Clutch boss 5
2. Install:
Lock washer
Nut (clutch boss) 1
NOTE:
Use the clutch holding tool 2 to hold the clutch
boss.
ÅFor USA and CDN
ıExcept for USA and CDN
3. Bend:
Lock washer tab
Clutch holding tool:
YM-91042/90890-04086
New
T R..60 Nm (6.0 m · kg, 43 ft · lb)
Å
ı
4. Install:
Friction plate 1
Clutch plate 2
NOTE:
Install the clutch plates and friction plates
alternately on the clutch boss, starting with a
friction plate and ending with a friction plate.
Apply the engine oil on the friction plates and
clutch plates.
Be sure to install a clutch plate with projec-
tion a offset approximately 90˚ from previ-
ous plates projection. Continue this
procedure in a clockwise direction until all
clutch plates are installed.

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

4 - 52
ENGOIL PUMP
Oil strainer
1. Inspect:
Oil strainer
Cracks/damage → Replace.
Contamination → Clean the flushing oil.
ASSEMBLY AND INSTALLATION
Oil pump
1. Install:
Oil pump housing 1
Outer rotor 2
Inner rotor 3
Pin 4
Oil pump shaft 5
Pin 6
Oil pump cover 7
Washer 8
Circlip 9
Conical spring washer 0
Oil pump driven gear A
Circlip B
Screws C
NOTE:
Apply engine oil onto the outer rotor, inner
rotor and oil pump shaft.
Install the conical spring washer in the direc-
tion as shown.
2. Install:
Oil strainer
Gasket
Oil pump assembly
Screws (oil pump assembly)
NOTE:
Apply engine oil onto the crankcase oil pas-
sage and oil pump assembly.
New
New
T R..5 Nm (0.5 m · kg, 3.6 ft · lb)
New
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
3. Install:
Oil pump drive gear 1
Rotary filter 2
NOTE:
Install the oil pump drive gear with its groove
a facing the engine.
Install the rotary filter with the dog b facing
out.
Align the rotary filter dog b with groove c of
the crankshaft.

4 - 53
ENGKICK AXLE AND SHIFT SHAFT
KICK AXLE AND SHIFT SHAFT
KICK AXLE AND SHIFT SHAFT
Extent of removal:1 Kick axle removal2 Shift shaft removal
Extent of removal Order Part name Q’ty Remarks
KICK AXLE AND SHIFT SHAFT
REMOVAL
Preparation for removal Shift pedal link Refer to “ENGINE REMOVAL” section.
Clutch Refer to “CLUTCH AND PRIMARY
DRIVEN GEAR” section.
1 Kick axle assembly 1 Refer to “REMOVAL POINTS”.
2 Circlip 1
3 Washer 1
4 Kick idle gear 1
5 Washer 1
6 Circlip 1
7 Shift shaft 1
8 Circlip 1
9 Torsion spring 1
10 Bolt (stopper lever) 1
11 Stopper lever 1
12 Spring 1
13 Segment 1 Refer to “REMOVAL POINTS”.
1
2