Page 16 of 508
EC080000
HOW TO USE
THIS MANUAL
EC081000
PARTICULARLY IMPORTANT
INFORMATION
The Safety Alert Symbol means ATTENTION!
BECOME ALERT! YOUR SAFETY IS
INVOLVED!
Failure to follow WARNING instructions could
result in severe injury or death to the machine
operator, a bystander, or a person inspecting
or repairing the machine.
A CAUTION indicates special precautions that
must be taken to avoid damage to the
machine.
NOTE:
A NOTE provides key information to make pro-
cedures easier or clearer.
FINDING THE REQUIRED PAGE
1. This manual consists of six chapters;
“General Information”, “Specifications”,
“Regular inspection and adjustments”,
“Engine”, “Chassis” and “Electrical”.
2. The table of contents is at the beginning
of the manual. Look over the general lay-
out of the book before finding then
required chapter and item.
Bend the book at its edge, as shown, to
find the required fore edge symbol mark
and go to a page for required item and
description.
WARNING
CAUTION:
Page 20 of 508

ILLUSTRATED SYMBOLS
(Refer to the illustration)
Illustrated symbols
1
to
6
are designed as
thumb tabs to indicate the chapter’s number
and content.
1
General information
2
Specifications
3
Regular inspection and adjustments
4
Engine
5
Chassis
6
Electrical
Illustrated symbols
7
to
D
are used to identify
the specifications appearing in the text.
7
With engine mounted
8
Special tool
9
Filling fluid
0
Lubricant
ATightening
BSpecified value, Service limit
CEngine speed
DResistance (W), Voltage (V), Electric current (A)
Illustrated symbols E to H in the exploded
diagrams indicate grade of lubricant and loca-
tion of lubrication point.
EApply engine oil
FApply molybdenum disulfide oil
GApply lightweight lithium-soap base grease
HApply molybdenum disulfide grease
Illustrated symbols I to J in the exploded
diagrams indicate where to apply a locking
agent and when to install new parts.
IApply locking agent (LOCTITE®)
JUse new one 12
34
56
78
90
AB
CD
EF
GH
IJ
GEN
INFOSPEC
INSP
ADJENG
CHAS–+ELEC
T R..
EM
LSM
LTNew
Page 22 of 508
INDEX
GENERAL
INFORMATION
SPECIFICATIONS
REGULAR
INSPECTION AND
ADJUSTMENT
ENGINE
CHASSIS
ELECTRICAL
Page 24 of 508

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
...................... 1-15
TT-R125
.............................................. 1-15
TT-R125LW
........................................ 1-16
CLEANING AND STORAGE
................... 1-17
CHAPTER 2
SPECIFICATIONS
GENERAL SPECIFICATIONS
................... 2-1
TT-R125
................................................ 2-1
TT-R125LW
.......................................... 2-4
MAINTENANCE SPECIFICATIONS
......... 2-7
ENGINE
................................................... 2-7
CHASSIS
............................................... 2-15
TT-R125
.............................................. 2-15
TT-R125LW
........................................ 2-19
ELECTRICAL
........................................ 2-23
GENERAL TORQUE
SPECIFICATIONS
.................................. 2-24
DEFINITION OF UNITS
.......................... 2-24
CABLE ROUTING DIAGRAM
................ 2-25
CHAPTER 3
REGULAR INSPECTION AND
ADJUSTMENTS
MAINTENANCE INTERVALS
................... 3-1
PRE-OPERATION INSPECTION
AND MAINTENANCE
............................... 3-3
ENGINE
..................................................... 3-4
CHASSIS
................................................. 3-15
ELECTRICAL
.......................................... 3-29
Page 26 of 508

CHAPTER 4
ENGINE
SEAT, FUEL TANK
AND SIDE COVERS
................................. 4-1
MUFFLER
................................................. 4-2
CARBURETOR
......................................... 4-3
CYLINDER HEAD
................................... 4-12
CAMSHAFT AND ROCKER ARMS
....... 4-20
VALVES AND VALVE SPRINGS
........... 4-24
CYLINDER AND PISTON
....................... 4-32
CLUTCH AND PRIMARY
DRIVEN GEAR
........................................ 4-40
OIL PUMP
............................................... 4-49
KICK AXLE AND SHIFT SHAFT
............ 4-53
CDI MAGNETO
....................................... 4-58
ENGINE REMOVAL
................................ 4-61
CRANKCASE, CRANKSHAFT
AND BALANCER
.................................... 4-65
TRANSMISSION, SHIFT CAM
AND SHIFT FORK
.................................. 4-73
CHAPTER 5
CHASSIS
FRONT WHEEL AND FRONT BRAKE
(TT-R125)
................................................... 5-1
FRONT WHEEL (TT-R125LW)
.................. 5-8
FRONT BRAKE (TT-R125LW)
................ 5-12
REAR WHEEL AND REAR BRAKE
....... 5-24
FRONT FORK
......................................... 5-32
HANDLEBAR
.......................................... 5-41
STEERING
.............................................. 5-49
SWINGARM
............................................ 5-55
REAR SHOCK ABSORBER
ASSEMBLY
.............................................. 5-62
CHAPTER 6
ELECTRICAL
ELECTRICAL COMPONENTS
AND WIRING DIAGRAM
.......................... 6-1
IGNITION SYSTEM
................................... 6-2
Page 72 of 508
SPEC
2 - 3
GENERAL SPECIFICATIONS
Brake:
Front brake type Drum brake
Operation Right hand operation
Rear brake type Drum brake
Operation Right foot operation
Suspension:
Front suspension Telescopic fork
Rear suspension Swingarm (link type monocross suspension)
Shock absorber:
Front shock absorber Coil spring/oil damper
Rear shock absorber Coil spring/gas, oil damper
Wheel travel:
Front wheel travel 180 mm (7.09 in)
Rear wheel travel 160 mm (6.30 in)
Electrical:
Ignition system CDI magneto
Page 75 of 508
SPEC
2 - 6
GENERAL SPECIFICATIONS
Brake:
Front brake type Single disc brake
Operation Right hand operation
Rear brake type Drum brake
Operation Right foot operation
Suspension:
Front suspension Telescopic fork
Rear suspension Swingarm (link type monocross suspension)
Shock absorber:
Front shock absorber Coil spring/oil damper
Rear shock absorber Coil spring/gas, oil damper
Wheel travel:
Front wheel travel 180 mm (7.09 in)
Rear wheel travel 168 mm (6.61 in)
Electrical:
Ignition system CDI magneto
Page 92 of 508
SPEC
2 - 23
MAINTENANCE SPECIFICATIONS
EC212300
ELECTRICAL
Item Standard Limit
CDI:
Magneto-model/manufacturer 5HP-00/YAMAHA ----
Charging coil resistance (color) 688 ~ 1,032 W at 20 ˚C (68 ˚F)
(Green-Brown)----
Pickup coil resistance (color) 248 ~ 372 W at 20 ˚C (68 ˚F)
(White/Red)----
CDI unit-model/manufacturer 5HP-00/YAMAHA ----
Ignition coil:
Model/manufacturer 4KJ-10/YAMAHA ----
Minimum spark gap 6 mm (0.24 in) ----
Primary coil resistance 0.18 ~ 0.28 W at 20 ˚C (68 ˚F) ----
Secondary coil resistance 6.3 ~ 9.5 kW at 20 ˚C (68 ˚F) ----
Part to be tightened Thread size Q’tyTightening torque
Nm m•kg ft•lb
Pickup coil M6 ´ 1.0 2 10 1.0 7.2
Blind plug (neutral switch) M10 ´ 1.25 1 20 2.0 14
Stator M6 ´ 1.0 3 10 1.0 7.2
RotorM12 ´ 1.25 1 80 8.0 58
Ignition coil M6 ´ 1.0 2 7 0.7 5.1