2003 YAMAHA TTR125 maintenance

INTRODUCTION
Congratulations on your purchase of a
Yamaha TT-R125E(R)/TT-R125LWE(R). This
model is the culmination of Yamaha’s vast
experience in the production of pacesetting
racing machines. It represents the highest
grade of craftsmanship and reliability that have
made Yamaha a leader.
This manual explains operation, inspection,
basic maintenance and tuning of your
machine. If you have any questions about this
manual or your machine, please contact your
Yamaha dealer.
NOTE:

As improvements are made on this model,
some data in this manual may become out-
dated. If you have any questions, please con-
sult your Yamaha dealer.
WARNING


READ THIS MANUAL CAREFULLY FOR
INSTRUCTIONS ON HOW TO PROPERLY
OPERATE THIS MACHINE.

ADULT INSTRUCTION AND SUPERVI-
SION ARE REQUIRED.

WEIGHT OF THE RIDER SHOULD NOT
EXCEED 68 kg (150 lb). (TT-R125E ONLY)

ALWAYS WEAR A HELMET AND SUIT-
ABLE PROTECTIVE CLOTHING WHEN
RIDING.

DO NOT TOUCH ANY MOVING PARTS OR
HEATED AREAS.

ALWAYS PERFORM PRE-OPERATION
CHECKS. REFER TO PAGE 3-3.

THIS MACHINE IS DESIGNED TO CARRY
THE OPERATOR ONLY.
NO PASSENGERS.

THIS MACHINE IS DESIGNED OFF-ROAD
USE ONLY.
IT IS NOT SUITABLE FOR ON-ROAD USE.

EC050000
TO THE NEW OWNER
This manual will provide you with a good basic
understanding of features, operation, and
basic maintenance and inspection items of this
machine. Please read this manual carefully
and completely before operating your new
machine. If you have any questions regarding
the operation or maintenance of your machine,
please consult your Yamaha dealer.
NOTE:

This manual should be considered a perma-
nent part of this machine and should remain
with it even if the machine is subsequently
sold.
EC060000
NOTICE
Some data in this manual may become out-
dated due to improvements made to this
model in the future. If there is any question
you have regarding this manual or your
machine, please consult your Yamaha
dealer.

EC0A0000
CONTENTS
CHAPTER 1
GENERAL INFORMATION
DESCRIPTION
...........................................1-1
MACHINE IDENTIFICATION
.....................1-2
IMPORTANT INFORMATION
....................1-3
CHECKING OF CONNECTION
.................1-5
SPECIAL TOOLS
......................................1-6
CONTROL FUNCTIONS
............................1-9
FUEL
........................................................1-12
STARTING AND BREAK-IN
....................1-13
TORQUE-CHECK POINTS
......................1-16
TT-R125E
............................................1-16
TT-R125LWE
.......................................1-17
CLEANING AND STORAGE
...................1-18
CHAPTER 2
SPECIFICATIONS
GENERAL SPECIFICATIONS
....................2-1
TT-R125E
..............................................2-1
TT-R125LWE
.........................................2-4
MAINTENANCE SPECIFICATIONS
..........2-7
ENGINE
....................................................2-7
CHASSIS
................................................2-15
TT-R125E
............................................2-15
TT-R125LWE
.......................................2-19
ELECTRICAL
.........................................2-23
GENERAL TORQUE
SPECIFICATIONS
...................................2-25
DEFINITION OF UNITS
...........................2-25
CABLE ROUTING DIAGRAM
.................2-26
CHAPTER 3
REGULAR INSPECTION AND
ADJUSTMENTS
MAINTENANCE INTERVALS
...................3-1
PRE-OPERATION INSPECTION
AND MAINTENANCE
................................3-3
ENGINE
......................................................3-4
CHASSIS
.................................................3-15
ELECTRICAL
...........................................3-32

1 - 15
GEN
INFO
STARTING AND BREAK-IN
BREAKING IN AFTER REPLACEMENT
After a part is replaced with a new one, it is
necessary to break it in as in a new machine.
This is required especially when the following
engine-related parts are replaced.
Cylinder
Piston
Piston ring
Valve
Camshaft
Crankshaft
Clutch
Transmission gear
Shift fork
* For warming up and inspection during
break-in, refer to “GENERAL INSPECTION
AND MAINTENANCE” section in the
CHAPTER 3 and if there is any problem,
stop the engine immediately and check.

1 - 16
GEN
INFO
TORQUE-CHECK POINTS
TORQUE-CHECK POINTS
TT-R125E
Engine mounting
Muffler
Steering Steering stem to
handlebar
Suspension Front Steering stem to
front fork
Rear For link type
Rear Installation of shock
absorber
Rear Installation of swing-
arm
Wheel Installation of wheel Front
Rear
Brake Front
Rear
Fuel systemFrame to engine
Frame to engine bracket
Engine bracket to engine
Muffler to cylinder head
Muffler to rear fender bracket
Muffler to seat pillar tube
Steering stem to frame
Steering stem to upper bracket
Upper bracket to handlebar
Front fork to upper bracket
Front fork to lower bracket
Assembly of links
Link to frame
Link to shock absorber
Link to swingarm
Shock absorber to frame
Tightening of pivot shaft
Tightening of wheel axle
Tightening of wheel axle
Wheel to sprocket
Camshaft lever to camshaft
Camshaft lever to camshaft
Fuel tank to fuel cock
NOTE:
Concerning the tightening torque, refer to
“MAINTENANCE SPECIFICATIONS” section
in the CHAPTER 2.

1 - 17
GEN
INFO
TORQUE-CHECK POINTS
TT-R125LWE
Engine mounting
Muffler
Steering Steering stem to
handlebar
Suspension Front Steering stem to
front fork
Rear For link type
Rear Installation of shock
absorber
Rear Installation of swing-
arm
Wheel Installation of wheel Front
Rear
Brake Front
Rear
Fuel systemFrame to engine
Frame to engine bracket
Engine bracket to engine
Muffler to cylinder head
Muffler to rear fender bracket
Muffler to seat pillar tube
Steering stem to frame
Steering stem to upper bracket
Upper bracket to handlebar
Front fork to upper bracket
Front fork to lower bracket
Assembly of links
Link to frame
Link to shock absorber
Link to swingarm
Shock absorber to frame
Tightening of pivot shaft
Tightening of wheel axle
Tightening of wheel axle
Wheel to sprocket
Brake caliper to front fork
Brake disc to wheel
Tightening of union bolt
Brake master cylinder to joint
Brake hose to joint
Brake master cylinder to handlebar
Tightening of bleed screw
Brake camshaft lever to brake camshaft
Fuel tank to fuel cock
NOTE:
Concerning the tightening torque, refer to
“MAINTENANCE SPECIFICATIONS” section
in the CHAPTER 2.

SPEC

2 - 7
MAINTENANCE SPECIFICATIONS
EC212000
MAINTENANCE SPECIFICATIONS
EC212100
ENGINE
Item Standard Limit
Cylinder head:
Warp limit ---- 0.03 mm
(0.0012 in)
Cylinder:
Bore size 54.000 ~ 54.019 mm
(2.1260 ~ 2.1267 in)----
Out of round limit ---- 0.05 mm
(0.0020 in)
Camshaft:
Drive method Chain drive (left) ----
Cam dimensions
Intake“A”25.881 ~ 25.981 mm
(1.0189 ~ 1.0229 in)25.851 mm
(1.0178 in)
“B”21.195 ~ 21.295 mm
(0.8344 ~ 0.8384 in)21.165 mm
(0.8333 in)
Exhaust“A”25.841 ~ 25.941 mm
(1.0174 ~ 1.0213 in)25.811 mm
(1.0162 in)
“B”21.050 ~ 21.150 mm
(0.8287 ~ 0.8327 in)21.020 mm
(0.8276 in)
Camshaft runout limit ---- 0.03 mm
(0.0012 in)

SPEC

2 - 8
MAINTENANCE SPECIFICATIONS
Cam chain:
Cam chain type/No. of links DID25SD DHA/88 ----
Cam chain adjustment method Automatic ----
Rocker arm/rocker arm shaft:
Shaft outside diameter 9.981 ~ 9.991 mm
(0.3930 ~ 0.3933 in)9.95 mm
(0.3917 in)
Rocker arm inside diameter 10.000 ~ 10.015 mm
(0.3937 ~ 0.3943 in)10.03 mm
(0.3949 in)
Valve, valve seat, valve guide:
Valve clearance (cold) IN 0.08 ~ 0.12 mm
(0.0031 ~ 0.0047 in)----
EX 0.10 ~ 0.14 mm
(0.0039 ~ 0.0055 in)----
Valve dimensions:
“A” head diameter IN 25.9 ~ 26.1 mm
(1.0197 ~ 1.0276 in)----
EX 21.9 ~ 22.1 mm
(0.8622 ~ 0.8701 in)----
“B” face width IN 1.1 ~ 3.0 mm
(0.0433 ~ 0.1181 in)----
EX 1.7 ~ 2.8 mm
(0.0669 ~ 0.1102 in)----
“C” seat width IN0.9 ~ 1.1 mm
(0.0354 ~ 0.0433 in)1.6 mm
(0.0630 in)
EX 0.9 ~ 1.1 mm
(0.0354 ~ 0.0433 in)1.6 mm
(0.0630 in)
“D” margin thickness IN 0.4 ~ 0.8 mm
(0.0157 ~ 0.0315 in)----
EX 0.8 ~ 1.2 mm
(0.0315 ~ 0.0472 in)----
Stem outside diameter IN4.975 ~ 4.990 mm
(0.1959 ~ 0.1965 in)4.950 mm
(0.1949 in)
EX 4.960 ~ 4.975 mm
(0.1953 ~ 0.1959 in)4.935 mm
(0.1943 in)
Guide inside diameter IN 5.000 ~ 5.012 mm
(0.1969 ~ 0.1973 in)5.042 mm
(0.1985 in)
EX 5.000 ~ 5.012 mm
(0.1969 ~ 0.1973 in)5.042 mm
(0.1985 in)
Stem-to-guide clearance IN0.010 ~ 0.037 mm
(0.0004 ~ 0.0015 in)0.08 mm
(0.0031 in)
EX 0.025 ~ 0.052 mm
(0.0010 ~ 0.0020 in)0.10 mm
(0.0040 in) Item Standard Limit
Head diameter
B
Face widthC
Seat width
D
Margin thicknessA