2003 YAMAHA TTR125 clutch

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

1 - 1
GEN
INFO

DESCRIPTION
EC100000
GENERAL INFORMATION
EC110000
DESCRIPTION
1
Clutch lever
2
Engine stop switch
3
Starter knob
4
Front brake lever
5
Throttle grip
6
Fuel tank cap
7
Air filter
8
Kickstarter crank
9
Fuel tank
0
Dipstick
A
Rear brake pedal
B
Fuel cock
C
Drive chain
D
Shift pedal
E
Front fork
*The illustration shows the TT-R125LW.
NOTE:


The machine you have purchased may differ
slightly from those shown in the following.

Designs and specifications are subject to
change without notice.

1 - 7
GEN
INFO
SPECIAL TOOLS
YM-1312-A, 90890-01312Fuel level gauge
This gauge is used to measure the fuel level in the
float chamber.YM-1312-A 90890-01312
YU-33270-B, 90890-01362 Flywheel puller
This tool is used to remove the rotor.YU-33270-B 90890-01362
YM-33963, 90890-01367
YM-33281, 90890-01400Fork seal driver weight
Fork seal driver attachment
These tools are used to installing the fork oil seal.YM-33963
YM-3328190890-01367
90890-01400
YU-33975, 90890-01403 Steering nut wrench
This tool is used when tighten the steering ring nut to
specification.YU-33975 90890-01403
YS-1880-A, 90890-01701 Sheave holder
This tool is used for when loosening or tightening the
flywheel magneto securing nut.YS-1880-A 90890-01701
YU-3112-C, 90890-03112 Pocket tester
Use this tool to inspect the coil resistance, output
voltage and amperage.YU-3112-C 90890-03112
YU-8036-B
90890-03113Inductive tachometer
Engine tachometer
This tool is needed for observing engine rpm.YU-8036-B 90890-03113
YM-4019, 90890-04019 Valve spring compressor
This tool is needed to remove and install the valve
assemblies.YM-4019 90890-04019
YM-91042, 90890-04086 Clutch holding tool
This tool is used to hold the clutch when removing or
installing the clutch boss securing nut.YM-91042 90890-04086
Part number Tool name/How to use Illustration

1 - 9
GEN
INFO
CONTROL FUNCTIONS
EC150000
CONTROL FUNCTIONS
ENGINE STOP SWITCH
The engine stop switch 1 is located on the left
handlebar. Continue pushing the engine stop
switch till the engine comes to a stop.
EC152000
CLUTCH LEVER
The clutch lever 1 is located on the left han-
dlebar; it disengages or engages the clutch.
Pull the clutch lever to the handlebar to disen-
gage the clutch, and release the lever to
engage the clutch. The lever should be pulled
rapidly and released slowly for smooth starts.
EC153000
SHIFT PEDAL
The gear ratios of the constant-mesh 5 speed
transmission are ideally spaced. The gears
can be shifted by using the shift pedal 1 on
the left side of the engine.
KICKSTARTER CRANK
WARNING
Before starting the engine, be sure to shift
the transmission into neutral.
Rotate the kickstarter crank 1 away from the
engine. Push the starter down lightly with your
foot until the gears engage, then kick smoothly
and forcefully to start the engine.
EC155001
THROTTLE GRIP
The throttle grip 1 is located on the right han-
dlebar; it accelerates or decelerates the
engine. For acceleration, turn the grip toward
you; for deceleration, turn it away from you.

1 - 14
GEN
INFO
STARTING AND BREAK-IN
BREAK-IN
Break-in is important to better fit the moving
and sliding parts as well as the installed parts.
It is also important to accustom the rider to the
machine better.
Avoid full-throttle run on a new machine for the
first 5 hours.
After the trial run, check for loose parts, oil
leakage and other problems.
Make full inspection and adjustment especially
of slack cables and drive chain and loose
spokes.
CAUTION:
After the break-in or before each ride, you
must check the entire machine for loose fit-
tings and fasteners as per “TORQUE-
CHECK POINTS”.
Tighten all such fasteners as required.
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” and if there is any
problem, stop the engine immediately and
check.

SPEC
2 - 2
GENERAL SPECIFICATIONS
Oil capacity:
Engine oil
Periodic oil change 1.0 L (0.88 Imp qt, 1.06 US qt)
Total amount 1.2 L (1.06 Imp qt, 1.27 US qt)
Air filter: Wet type element
Fuel:
Type Unleaded gasoline only (USA, AUS, NZ)
Regular unleaded gasoline only
(CDN, EUROPE)
Regular gasoline (ZA)
Tank capacity 6.6 L (1.45 Imp gal, 1.74 US gal)
Reserve amount 1.9 L (0.42 Imp gal, 0.5 US gal)
Carburetor:
Type VM20SS
Manufacturer MIKUNI
Spark plug:
Type CR7HSA/U22FSR-U
Manufacturer NGK/DENSO
Gap 0.6 ~ 0.7 mm (0.02 ~ 0.03 in)
Clutch type: Wet, multiple-disc
Transmission:
Primary reduction system Gear
Primary reduction ratio 68/19 (3.579)
Secondary reduction system Chain drive
Secondary reduction ratio 49/13 (3.769)
Transmission type Constant mesh, 5-speed
Operation Left foot operation
Gear ratio: 1st 37/14 (2.643)
2nd 32/18 (1.778)
3rd 25/19 (1.316)
4th 23/22 (1.045)
5th 21/24 (0.875)
Chassis:
Frame type Diamond
Caster angle 28.7˚
Trail 93 mm (3.66 in)
Tire:
Type With tube
Size (front) 70/100-17 40M
Size (rear) 90/100-14 49M
Manufacturer (front and rear) CHENG SHIN
Tire pressure (front and rear) 100 kPa (1.00 kgf/cm
2, 15 psi)

2

SPEC
2 - 5
GENERAL SPECIFICATIONS
Oil capacity:
Engine oil
Periodic oil change 1.0 L (0.88 Imp qt, 1.06 US qt)
Total amount 1.2 L (1.06 Imp qt, 1.27 US qt)
Air filter: Wet type element
Fuel:
Type Unleaded gasoline only (USA, AUS, NZ)
Regular unleaded gasoline only
(CDN, EUROPE)
Regular gasoline (ZA)
Tank capacity 6.6 L (1.45 Imp gal, 1.74 US gal)
Reserve amount 1.9 L (0.42 Imp gal, 0.5 US gal)
Carburetor:
Type VM20SS
Manufacturer MIKUNI
Spark plug:
Type CR7HSA/U22FSR-U
Manufacturer NGK/DENSO
Gap 0.6 ~ 0.7 mm (0.02 ~ 0.03 in)
Clutch type: Wet, multiple-disc
Transmission:
Primary reduction system Gear
Primary reduction ratio 68/19 (3.579)
Secondary reduction system Chain drive
Secondary reduction ratio 54/13 (4.154)
Transmission type Constant mesh, 5-speed
Operation Left foot operation
Gear ratio: 1st 37/14 (2.643)
2nd 32/18 (1.778)
3rd 25/19 (1.316)
4th 23/22 (1.045)
5th 21/24 (0.875)
Chassis:
Frame type Diamond
Caster angle 28.5˚
Trail 107 mm (4.21 in)
Tire:
Type With tube
Size (front) 70/100-19 42M
Size (rear) 90/100-16 52M
Manufacturer (front and rear) INOUE RUBBER
Tire pressure (front and rear) 100 kPa (1.00 kgf/cm
2, 15 psi)

SPEC
2 - 11
MAINTENANCE SPECIFICATIONS
Crankshaft:
Crank width “A”46.95 ~ 47.00 mm
(1.848 ~ 1.850 in)----
Runout limit “C”---- 0.03 mm
(0.0012 in)
Big end side clearance “D”0.15 ~ 0.45 mm
(0.0059 ~ 0.0177 in)0.5 mm
(0.02 in)
Clutch:
Friction plate thickness 2.92 ~ 3.08 mm
(0.115 ~ 0.121 in)2.8 mm
(0.110 in)
Quantity 5 ----
Clutch plate thickness 1.05 ~ 1.35 mm
(0.041 ~ 0.053 in)----
Quantity 4 ----
Warp limit ---- 0.2 mm
(0.008 in)
Clutch spring free length 33 mm (1.30 in) 31 mm
(1.22 in)
Quantity 4 ----
Clutch release method Inner push, cam push ----
Push rod bending limit ---- 0.5 mm
(0.020 in)
Shifter:
Shifter type Cam drum and guide bar ----
Kick starter:
Type Kick and mesh type ----
Kick clip friction force 6.4 ~ 13.2 N
(0.65 ~ 1.35 kg, 1.4 ~ 3.0 lb)----
Carburetor:
I.D. mark 5HP1 10 ----
Main jet (M.J) #105 ----
Main jet nozzle (N.J) N-6M ----
Main air jet (M.A.J)ø1.2 ----
Jet needle-clip position (J.N) 5HGM56-2 ----
Cutaway (C.A) 2.5 ----
Pilot air jet 1 (P.A.J.1) #80 ----
Pilot air jet 2 (P.A.J.2) #145 ----
Pilot outlet (P.O)ø1.05 ----
Pilot jet (P.J) #15 ----
Pilot air screw (example) (A.S) (2-1/2 ~ 3-1/2 turns out) ----
Bypass (B.P)ø1.0 ----
Needle valve seat size (V.S) 1.8 ----
Starter jet 1 (G.S.1) #22.5 ----
Starter jet 2 (G.S.2) #1.2 ----
Fuel level (F.L) 6.0 ~ 7.0 mm (0.24 ~ 0.28 in) ----
Engine idle speed 1,300 ~ 1,500 r/min ----Item Standard Limit