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
3 - 10
INSP
ADJOIL PRESSURE INSPECTION/PILOT AIR SCREW
ADJUSTMENT/ENGINE IDLING SPEED ADJUSTMENT
OIL PRESSURE INSPECTION
1. Check:
lOil pressure
Checking steps:
lSlightly loosen the oil pressure check bolt
1.
lStart the engine and keep it idling until oil
starts to seep from the oil pressure check
bolt. If no oil comes out after one minute,
turn the engine off so it will not seize.
lCheck oil passages and oil pump for dam-
age or leakage.
lStart the engine after solving the prob-
lem(s) and recheck the oil pressure.
lTighten the oil pressure check bolt.
T R..
Oil pressure check bolt:
7 Nm (0.7 m • kg, 5.1 ft • lb)
PILOT AIR SCREW ADJUSTMENT
1. Adjust:
lPilot air screw 1
Adjustment steps:
NOTE:
To optimize the fuel flow at a smaller throttle
opening, each machine’s pilot air screw has
been individually set at the factory. Before
adjusting the pilot air screw, turn it in fully
and count the number of turns. Record this
number as the factory-set number of turns
out.
lScrew in the pilot air screw until it is lightly
seated.
lBack out by the specified number of turns.
Pilot air screw:
2-1/2 ~ 3-1/2 turns out (example)
ENGINE IDLING SPEED ADJUSTMENT
1. Start the engine and thoroughly warm it
up.
2. Attach:
lInductive tachometer
To spark plug lead.
3. Adjust:
lEngine idling speed
