
CHAPTER 3
REGULAR INSPECTION
AND ADJUSTMENTS
MAINTENANCE INTERVALS ...................3-1
PRE-OPERATION INSPECTION
AND MAINTENANCE ................................3-3
ENGINE ......................................................3-4
CHASSIS .................................................3-15
ELECTRICAL ...........................................3-34
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
(TT-R125/TT-R125LW) ............................4-58
CDI MAGNETO AND STARTER
CLUTCH (TT-R125E/TT-R125LWE) .......4-61
ENGINE REMOVAL .................................4-66
CRANKCASE, CRANKSHAFT
AND BALANCER ....................................4-70
TRANSMISSION, SHIFT CAM
AND SHIFT FORK ...................................4-78

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-R125/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 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-R125LW/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 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 - 13
MAINTENANCE SPECIFICATIONS
Part to be tightened Thread size Q’tyTightening torque
Nm m•kg ft•lb
Spark plug M10 × 1.0 1 13 1.3 9.4
Cylinder head bolt M8 × 1.25 4 22 2.2 16
Cylinder head bolt M6 × 1.0 2 10 1.0 7.2
Oil pressure check bolt M6 × 1.0 1 7 0.7 5.1
Cylinder head side cover M6 × 1.0 2 10 1.0 7.2
Tappet cover M45 × 1.5 2 18 1.8 13
Timing chain guide M6 × 1.0 1 10 1.0 7.2
Adjusting screw (valve) and locknut M5 × 0.5 2 8 0.8 5.8
Camshaft sprocket M8 × 1.25 1 20 2.0 14
Bearing plate cover (camshaft) M6 × 1.0 1 10 1.0 7.2
Timing chain tensioner cap bolt M6 × 1.0 1 8 0.8 5.8
Timing chain tensioner M6 × 1.0 2 10 1.0 7.2
Oil pump assembly M6 × 1.0 2 7 0.7 5.1
Oil pump cover M5 × 0.8 1 5 0.5 3.6
Engine oil drain bolt M12 × 1.5 1 20 2.0 14
Carburetor joint M6 × 1.0 2 10 1.0 7.2
Carburetor joint clamp (air filter) M4 × 0.7 1 2 0.2 1.4
Coasting enricher cover M4 × 0.7 2 2 0.2 1.4
Air filter case M6 × 1.0 3 7 0.7 5.1
Muffler M6 × 1.0 2 10 1.0 7.2
Muffler M10 × 1.25 1 60 6.0 43
Muffler M8 × 1.25 1 30 3.0 22
Muffler guard M6 × 1.0 7 10 1.0 7.2
Spark arrester M6 × 1.0 3 10 1.0 7.2
Crankcase M6 × 1.0 10 10 1.0 7.2
Left crankcase cover M6 × 1.0 7 10 1.0 7.2
Drive sprocket cover M6 × 1.0 2 12 1.2 8.7
Right crankcase cover M6 × 1.0 9 10 1.0 7.2
Lead guide (CDI magneto lead) M6 × 1.0 1 7 0.7 5.1
Timing mark accessing screw M14 × 1.5 1 7 0.7 5.1
Crankshaft end accessing screw M32 × 1.5 1 7 0.7 5.1
Kickstarter crank M12 × 1.0 1 50 5.0 36
Starter clutch (TT-R125E/TT-R125LWE) M8 × 1.25 3 30 3.0 22
Plate (starter idle gear) (TT-R125E/TT-R125LWE) M6 × 1.0 2 7 0.7 5.1
Primary drive gear M12 × 1.0 1 70 7.0 50
Clutch spring M5 × 0.8 4 6 0.6 4.3
Clutch boss M12 × 1.0 1 60 6.0 43
Adjusting screw (push rod) and locknut M6 × 1.0 1 8 0.8 5.8
Bearing plate cover (main axle) M6 × 1.0 2 7 0.7 5.1
Drive sprocket M5 × 0.8 2 6 0.6 4.3
Shift arm M6 × 1.0 1 10 1.0 7.2
Shift rod and shift pedal M6 × 1.0 1 7 0.7 5.1
Shift rod and shift arm M6 × 1.0 1 7 0.7 5.1
Shift pedal M6 × 1.0 1 12 1.2 8.7

SPEC
2 - 17
MAINTENANCE SPECIFICATIONS
NOTE:
1. First, tighten the ring nut approximately 38 Nm (3.8 m • kg, 27 ft • lb) by using the ring nut
wrench and turn the steering right and left a few times; then loosen the ring nut one turn.
2. Retighten the ring nut 20 Nm (2.0 m • kg, 14 ft • lb). Part to be tightened Thread size Q’tyTightening torque
Nm m•kg ft•lb
Upper bracket and inner tube M8 × 1.25 2 25 2.5 18
Lower bracket and inner tube M10 × 1.25 2 60 6.0 43
Upper bracket and steering stem M22 × 1.0 1 110 11.0 80
Handlebar upper holder and upper bracket M8 × 1.25 4 23 2.3 17
Steering stem and ring nut M25 × 1.0 1 Refer to NOTE.
Front fork and cap bolt M25 × 1.0 2 23 2.3 17
Front fork and damper rod M10 × 1.0 2 23 2.3 17
Front fork and brake cable holder M6 × 1.0 1 7 0.7 5.1
Number plate M6 × 1.0 1 7 0.7 5.1
Starter knob M11 × 1.25 1 1 0.1 0.7
Starter knob stay M6 × 1.0 2 10 1.0 7.2
Grip cap upper and lower M5 × 0.8 2 4 0.4 2.9
Throttle cable cap M4 × 0.7 2 2 0.2 1.4
Brake lever mounting (bolt) M6 × 1.0 1 3 0.3 2.2
Brake lever mounting (nut) M6 × 1.0 1 4 0.4 2.9
Brake lever holder M5 × 0.8 2 4 0.4 2.9
Clutch lever mounting (bolt) M6 × 1.0 1 7 0.7 5.1
Clutch lever mounting (nut) M6 × 1.0 1 7 0.7 5.1
Clutch lever holder M5 × 0.8 2 4 0.4 2.9
Front wheel axle and axle nut M12 × 1.25 1 45 4.5 32
Front brake camshaft lever and camshaft M6 × 1.0 1 10 1.0 7.2
Rear wheel axle and axle nut M12 × 1.25 1 60 6.0 43
Rear brake camshaft lever and camshaft M6 × 1.0 1 10 1.0 7.2
Brake pedal mounting M10 × 1.25 1 30 3.0 22
Brake pedal position locknut M6 × 1.0 1 7 0.7 5.1
Front wheel nipple (spoke)—36 2 0.2 1.4
Rear wheel nipple (spoke)—36 3 0.3 2.2
Driven sprocket (nut) M10 × 1.25 4 43 4.3 31
Driven sprocket (stud) M10 × 1.25 4 30 3.0 22
Sidestand mounting (nut) M10 × 1.25 1 44 4.4 32
Engine mounting:
Engine bracket (front) and frame M8 × 1.25 2 40 4.0 29
Engine bracket (front) and engine M8 × 1.25 2 40 4.0 29
Engine bracket (upper) and frame M8 × 1.25 2 40 4.0 29
Engine bracket (upper) and cylinder head M8 × 1.25 1 40 4.0 29
Engine and frame (rear) M8 × 1.25 2 40 4.0 29
Pivot shaft and nut M12 × 1.25 1 53 5.3 38
Relay arm and swingarm M12 × 1.25 1 70 7.0 50

SPEC
2 - 21
MAINTENANCE SPECIFICATIONS
NOTE:
1. First, tighten the ring nut approximately 38 Nm (3.8 m • kg, 27 ft • lb) by using the ring nut
wrench and turn the steering right and left a few times; then loosen the ring nut one turn.
2. Retighten the ring nut 20 Nm (2.0 m • kg, 14 ft • lb). Part to be tightened Thread size Q’tyTightening torque
Nm m•kg ft•lb
Upper bracket and inner tube M8 × 1.25 2 25 2.5 18
Lower bracket and inner tube M10 × 1.25 2 60 6.0 43
Upper bracket and steering stem M22 × 1.0 1 110 11.0 80
Handlebar upper holder and upper bracket M8 × 1.25 4 23 2.3 17
Steering stem and ring nut M25 × 1.0 1 Refer to NOTE.
Front fork and cap bolt M25 × 1.0 2 23 2.3 17
Front fork and damper rod M10 × 1.0 2 23 2.3 17
Front fork and brake hose holder M6 × 1.0 2 7 0.7 5.1
Number plate M6 × 1.0 1 7 0.7 5.1
Starter knob M11 × 1.25 1 1 0.1 0.7
Starter knob stay M6 × 1.0 2 10 1.0 7.2
Grip cap upper and lower M5 × 0.8 2 4 0.4 2.9
Throttle cable cap M4 × 0.7 2 2 0.2 1.4
Front brake master cylinder M6 × 1.0 2 9 0.9 6.5
Front brake master cylinder cap M4 × 0.7 2 2 0.2 1.4
Brake lever mounting (bolt) M6 × 1.0 1 7 0.7 5.1
Brake lever mounting (nut) M6 × 1.0 1 7 0.7 5.1
Brake lever adjuster and locknut M6 × 0.75 1 4 0.4 2.9
Clutch lever mounting (bolt) M6 × 1.0 1 7 0.7 5.1
Clutch lever mounting (nut) M6 × 1.0 1 7 0.7 5.1
Clutch lever holder M5 × 0.8 2 4 0.4 2.9
Front brake master cylinder and joint M10 × 1.25 1 26 2.6 19
Front brake hose and joint M10 × 1.25 1 14 1.4 10
Front brake hose union bolt M10 × 1.25 1 26 2.6 19
Front brake caliper and front fork M8 × 1.25 2 30 3.0 22
Brake caliper support bolt M8 × 1.25 1 22 2.2 16
Front brake caliper and bleed screw M7 × 1.0 1 6 0.6 4.3
Front wheel axle and axle nut M12 × 1.25 1 45 4.5 32
Front brake disc and wheel hub M6 × 1.0 4 12 1.2 8.7
Rear wheel axle and axle nut M12 × 1.25 1 60 6.0 43
Rear brake camshaft lever and camshaft M6 × 1.0 1 10 1.0 7.2
Brake pedal mounting M10 × 1.25 1 30 3.0 22
Brake pedal position locknut M6 × 1.0 1 7 0.7 5.1
Front wheel nipple (spoke)—36 2 0.2 1.4
Rear wheel nipple (spoke)—36 3 0.3 2.2