2000 YAMAHA TTR125 brake

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
.... 5-1
REAR WHEEL AND REAR BRAKE
......... 5-8
FRONT FORK
......................................... 5-16
HANDLEBAR
.......................................... 5-25
STEERING
.............................................. 5-31
SWINGARM
............................................ 5-37
REAR SHOCK ABSORBER
................... 5-44
CHAPTER 6
ELECTRICAL
ELECTRICAL COMPONENTS
AND WIRING DIAGRAM
.......................... 6-1
IGNITION SYSTEM
................................... 6-2

GEN
INFO

1 - 1
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
NOTE:

l
The machine you have purchased may differ
slightly from those shown in the following.
l
Designs and specifications are subject to
change without notice.
1
1

1 - 10
GEN
INFO
CONTROL FUNCTIONS
EC156000
FRONT BRAKE LEVER
The front brake lever 1 is located on the right
handlebar. Pull it toward the handlebar to acti-
vate the front brake.
EC157000
REAR BRAKE PEDAL
The rear brake pedal 1 is located on the right
side of the machine. Press down on the brake
pedal to activate the rear brake.
EC158010
FUEL COCK
The fuel cock supplies fuel from the tank to
carburetor while filtering the fuel. The fuel cock
has the three positions:
OFF: With the lever in this position, fuel will
not flow. Always return the lever to this
position when the engine is not running.
ON: With the lever in this position, fuel flows
to the carburetor. Normal riding is done
with the lever in this position.
RES: This indicates reserve. If you run out of
fuel while riding, move the lever to this
position. FILL THE TANK AT THE
FIRST OPPORTUNITY. BE SURE TO
SET THE LEVER TO “ON” AFTER
REFUELING.
EC159000
STARTER KNOB (CHOKE)
When cold, the engine requires a richer air-fuel
mixture for starting. A separate starter circuit,
which is controlled by the starter knob 1, sup-
plies this mixture. Pull the starter knob out to
open the circuit for starting. When the engine
has warmed up, push it in to close the circuit.

GEN
INFO
1 - 15
TORQUE-CHECK POINTS
TORQUE-CHECK POINTS
Engine mounting
Steering Steering shaft to
handlebar
Suspension Front Steering shaft 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
Steering shaft to frame
Steering shaft 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 - 16
GEN
INFO
CLEANING AND STORAGE
EC1B0000
CLEANING AND STORAGE
EC1B1000
CLEANING
Frequent cleaning of your machine will
enhance its appearance, maintain good over-
all performance, and extend the life of many
components.
1. Before washing the machine, block off
the end of the exhaust pipe to prevent
water from entering. A plastic bag
secured with a rubber band may be used
for this purpose.
2. If the engine is excessively greasy, apply
some degreaser to it with a paint brush.
Do not apply degreaser to the chain,
sprockets, or wheel axles.
3. Rinse the dirt and degreaser off with a
garden hose; use only enough pressure
to do the job.
CAUTION:
Excessive hose pressure may cause water
seepage and contamination of wheel bear-
ings, front forks, brakes and transmission
seals. Many expensive repair bills have
resulted from improper high pressure
detergent applications such as those avail-
able in coin-operated car washers.
4. After the majority of the dirt has been
hosed off, wash all surfaces with warm
water and a mild detergent. Use an old
toothbrush to clean hard-to-reach places.
5. Rinse the machine off immediately with
clean water, and dry all surfaces with a
soft towel or cloth.
6. Immediately after washing, remove
excess water from the chain with a paper
towel and lubricate the chain to prevent
rust.
7. Clean the seat with a vinyl upholstery
cleaner to keep the cover pliable and
glossy.
8. Automotive wax may be applied to all
painted or chromed surfaces. Avoid com-
bination cleaner-waxes, as they may con-
tain abrasives.
9. After completing the above, start the
engine and allow it to idle for several min-
utes.

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

SPEC

2 - 12
MAINTENANCE SPECIFICATIONS
EC212201
CHASSIS
Item Standard Limit
Steering system:
Steering bearing type (upper) Angular bearing ----
(lower) Taper roller bearing ----
Front suspension:
Front fork travel 180 mm (7.09 in) ----
Fork spring free length 327 mm (12.87 in) 322 mm (12.68 in)
Spring rate, STD K = 3.00 N/mm
(0.310 kg/mm, 17.4 lb/in)----
Optional spring/spacer No ----
Oil capacity 159 cm
3


(5.60 Imp oz, 5.38 US oz)----
Oil level 122 mm (4.80 in) ----
Oil grade Fork oil 10W or equivalent ----
Inner tube outer diameter 30 mm (1.18 in) ----
Front fork top end Zero mm (Zero in) ----
Rear suspension:
Shock absorber travel 65 mm (2.56 in) ----
Spring free length 175 mm (6.89 in) ----
Fitting length 165 mm (6.50 in) ----
Spring rate, STD K = 48.1 N/mm
(4.9 kg/mm, 274 lb/in)----
Optional spring No ----
Enclosed gas pressure 1,500 kPa
(15 kg/cm
2

, 213 psi)----
Wheel:
Front wheel type Spoke wheel ----
Rear wheel type Spoke wheel ----
Front rim size/material 17 ´ 1.40/Steel ----
Rear rim size/material 14 ´ 1.60/Steel ----
Rim runout limit:
Radial ---- 2.0 mm (0.08 in)
Lateral ---- 2.0 mm (0.08 in)
Drive chain:
Type/manufacturer DID428 HG(I)/DAIDO ----
Number of links 116 links ----
Chain slack 35 ~ 60 mm (1.4 ~ 2.4 in) ----
Chain length (10 links) ----121.4 mm
(4.78 in)
Drum brake:
Front drum brake type Leading, trailing ----
Rear drum brake type Leading, trailing ----
Front drum inside diameter 110 mm (4.33 in) 111 mm (4.37 in)
Rear drum inside diameter 110 mm (4.33 in) 111 mm (4.37 in)
Front lining thickness 4.0 mm (0.16 in) 2.0 mm (0.08 in)
Rear lining thickness 4.0 mm (0.16 in) 2.0 mm (0.08 in)
Front shoe spring free length 50.5 mm (1.99 in) ----
Rear shoe spring free length 50.5 mm (1.99 in) ----

SPEC
2 - 13
MAINTENANCE SPECIFICATIONS
Brake lever and brake pedal:
Brake lever free play (lever end) 10 ~ 15 mm (0.39 ~ 0.59 in) ----
Brake pedal position
(vertical height below footrest top)1 mm (0.04 in) ----
Brake pedal free play 20 ~ 30 mm (0.79 ~ 1.18 in) ----
Clutch lever free play (lever end) 10 ~15 mm (0.39 ~ 0.59 in) ----
Throttle grip free play 3 ~ 5 mm (0.12 ~ 0.20 in) ----Item Standard Limit