Page 26 of 610

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 
     
        
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4 - 1
ENG
 
EC400000 
ENGINE 
EC4R0000 
SEAT, FUEL TANK AND SIDE COVERS 
Extent of removal:  
1  
 Seat removal  
2  
 Fuel tank removal  
3  
 Side covers removal  
4  
 Number plate removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removal 
SEAT, FUEL TANK AND SIDE 
COVERS REMOVAL  
Turn the fuel cock to “OFF”.
1 Seat 1
2 Air scoop (left and right) 2
3 Fuel hose 1 Remove on fuel tank side.
4 Fitting band 1
5 Bolt (fuel tank) 2
6 Fuel tank 1
7 Left side cover  1
8 Right side cover  1
9Number plate
1
13
4
2
3
 
SEAT, FUEL TANK AND SIDE COVERS 
     
        
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4 - 2
ENG
 
MUFFLER
MUFFLER 
Extent of removal: 
1  
 Muffler removal
Extent of removal Order Part name Q’ty Remarks  
MUFFLER REMOVAL  
Preparation for removal Right side cover Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
1 Bolt (spark arrester) 3
2 Spark arrester 1
3 Nut (muffler) 2
4 Bolt (muffler) 1
5Muffler
1
1 
     
        
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4 - 3
ENG
 
CARBURETOR
CARBURETOR 
Extent of removal: 
1  
 Carburetor removal
Extent of removal Order Part name Q’ty Remarks  
CARBURETOR REMOVAL  
Preparation for removal Fuel tank
Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Number plate
1 Fuel hose  1
2 Over flow hose  1
3 Air vent hose 2
4 Starter plunger/starter knob 1
5 Carburetor top cover 1
6 Clamp (air cleaner joint) 1 Loosen the screw (air cleaner joint).
7 Clamp (carburetor joint) 1 Loosen the screws (carburetor joint).
8Carburetor
1
1 
     
        
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4 - 12
ENGCYLINDER HEAD
CYLINDER HEAD
CYLINDER HEAD SIDE COVER AND TAPPET COVER
Extent of removal:1 Cylinder head side cover and tappet cover removal
Extent of removal Order Part name Q’ty Remarks
CYLINDER HEAD SIDE COVER 
AND TAPPET COVER 
REMOVAL
Preparation for removal Seat and fuel tank  Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Muffler Refer to “MUFFLER” section.
Carburetor Refer to “CARBURETOR” section.
CDI unit Remove from the frame. 
1 Engine bracket  1
2 Spark plug  1
3 Cylinder head side cover  1
4 Tappet cover  2
5 Crankshaft end accessing screw 1
6Timing mark accessing screw
1
1 
     
        
        Page 374 of 610
4 - 58
ENG
EC4L0000
CDI MAGNETO (TT-R125/TT-R125LW)
Extent of removal:1 CDI magneto removal
Extent of removal Order Part name Q’ty Remarks
CDI MAGNETO REMOVAL 
Preparation for removal Seat and fuel tank Refer to “SAET, FUEL TANK AND SIDE
COVERS” section.
Drain the engine oil Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
Drive sprocket cover Refer to “ENGINE REMOVAL” section.
1 CDI magneto lead 1
2 Left crankcase cover 1
3 Nut (rotor) 1
Use special tool.
Refer to “REMOVAL POINTS”.
4 Rotor 1
5 Woodruff key 1
6 Pickup coil 1
7 Lead guide 1
8Stator
1
1
CDI MAGNETO (TT-R125/TT-R125LW) 
     
        
        Page 380 of 610
4 - 61
ENG
CDI MAGNETO AND STARTER CLUTCH
(TT-R125E/TT-R125LWE)
CDI MAGNETO AND STARTER CLUTCH (TT-R125E/TT-R125LWE)
Extent of removal:1 Pickup coil/stator removal2 Starter clutch/wheel gear removal
Extent of removal Order Part name Q’ty Remarks
CDI MAGNETO AND STATOR 
REMOVAL 
Preparation for removal Fuel tank
1 CDI magneto lead 1
2 Neutral switch lead  1
3 Left crankcase cover 1
4 Nut (rotor) 1
Use special tool.
Refer to “REMOVAL POINTS”.
5 Rotor 1
6 Starter clutch  1
7 Woodruff key 1
8 Starter wheel gear 1
9 Plain washer 1
10 Plate (starter idle gear) 1
11 Starter idle gear 1
12 Lead guide 1
13Pickup coil/stator assembly
1
1
2
1
1 
     
        
        Page 390 of 610
4 - 66
ENGENGINE REMOVAL
ENGINE REMOVAL
Extent of removal:1 Engine removal
Extent of removal Order Part name Q’ty Remarks
ENGINE REMOVAL
Preparation for removal Hold the machine by placing the
suitable stand under the frame.
Seat, fuel tank and side covers Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Carburetor Refer to “CARBURETOR” section.
Muffler Refer to “MUFFLER” section.
Clutch cable Disconnect at engine side.
Spark plug cap
Disconnect the CDI magneto 
lead.
Disconnect the neutral switch lead 
for the TT-R125E/TT-R125LWE.
Starter motor for the TT-R125E/
TT-R125LWERefer to “ELECTRIC STARTING SYS-
TEM” section in the CHAPTER 6 for the
TT-R125E/TT-R125LWE.
Drain the engine oil. Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.