fuel YAMAHA TTR125 2002 Owner's Manual

2 - 25
SPEC

CABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1
Fuel tank breather hose
2
CDI unit
3
CDI unit band
4
Clamp
5
CDI magneto lead
6
Air vent hose
7
Wire harness
8
Engine stop switch lead
9
Cable guide
0
Brake cable
(Brake hose for the
TT-R125LW)
A
Brake cable holder
(Brake hose holder for the
TT-R125LW)

Fit the CDI unit band over the CDI unit bracket till it stops.
õ
Clamp the ignition coil lead.
‚
Clamp the wire harness coupler.
ë
Clamp the CDI magneto lead, throttle cable and starter cable.
ä
Clamp the CDI magneto lead so that it does not contact the push lever.
ì
Pass the air vent hoses between the engine and swingarm.
í
Clamp the wire harness and engine stop switch lead.
î
Pass the brake cable (brake hose for the TT-R125LW) into the cable guide.
é
Clamp the brake cable.
ï
Clamp the brake hose between the paint marks.

2 - 27
SPEC

CABLE ROUTING DIAGRAM
1
Engine stop switch lead
2
Engine stop switch
3
Fuel tank breather hose
4
Clamp
5
Brake cable
(Brake hose for the TT-R125LW)
6
Clutch cable
7Throttle cablePass the engine stop switch lead in the middle of the clutch holder.
õClamp the engine stop switch lead to the handlebar to 3 clicks.
‚Pass the brake cable (brake hose for the TT-R125LW) in front of the
number plate and through the cable guide.
ëPass the clutch cable in back of the number plate.
äInsert the fuel tank breather hose into the hole in the starter knob stay
more the 30 mm (1.18 in).
ìClamp the throttle cable adjuster cover to the handlebar with the clamp
ends downward.

3 - 1
INSP
ADJ

MAINTENANCE INTERVALS
EC300000
REGULAR INSPECTION AND ADJUSTMENTS
MAINTENANCE INTERVALS
The following schedule is intended as a general guide to maintenance and lubrication. Bear in mind
that such factors as weather, terrain, geographical location, and individual usage will alter the
required maintenance and lubrication intervals. If you are a doubt as to what intervals to follow in
maintaining and lubricating your machine, consult your Yamaha dealer.
Dealer
NoteItem Checks and maintenance jobsInitial Every
10 hours
(1 month)60 hours
(6 months)120 hours
(12 months)
*
Fuel lineCheck fuel hoses for cracks or damage.
Replace if necessary.
Spark plugCheck condition.
Clean, regap or replace if necessary.
*
ValvesCheck valve clearance.
Adjust if necessary.
Air filter Clean or replace element if necessary.
*
CarburetorCheck engine idling speed and starter operation.
Adjust if necessary.
Exhaust systemsCheck for leakage.
Retighten if necessary.
Replace gasket if necessary.
Engine oilCheck oil level and vehicle for oil leakage.
Correct if necessary.
Change. (Warm engine before draining.)
ClutchCheck operation.
Adjust or replace cable.
*
Front brakeCheck operation.
Adjust brake lever free play.
Check fluid level and leakage. (TT-R125LW only)Every ride
*
Rear brakeCheck operation.
Adjust brake pedal free play and replace brake
shoes if necessary.Every ride
*
WheelsCheck balance, runout, spoke tightness and for
damage.
Tighten spokes and rebalance, replace if
necessary.
*
TiresCheck tread depth and for damage.
Replace if necessary.
Check air pressure.
Correct if necessary.
*
Wheel bearingsCheck bearing for looseness or damage.
Replace if necessary.
*
SwingarmCheck swingarm pivoting point for play.
Correct if necessary.
Lubricate with molybdenum disulfide grease.
Drive chainCheck chain slack.
Adjust if necessary. Make sure that the rear wheel
is properly aligned.
Clean and lubricate.Every ride
*
Steering bearingsCheck bearing play and steering for roughness.
Correct accordingly.
Lubricate with lithium soap base grease every 120
hours.
SidestandCheck operation.
Lubricate and repair if necessary.
3

3 - 3
INSP
ADJ

PRE-OPERATION INSPECTION AND MAINTENANCE
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation or practice, make sure the machine is in good operating condi-
tion.
Before using this machine, check the following points.
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
FuelCheck that a fresh gasoline is filled in the fuel tank. Check the
fuel line for leakage.P.1-12
Engine oilCheck that the oil level is correct. Check the crankcase for leak-
age.P.3-7 ~ 10
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-4
Throttle grip/housingCheck that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary.P.3-4 ~ 5
BrakesCheck the play of front and rear brake and effect of front and
rear brake.
Check fluid level and leakage. (TT-R125LW only)P.3-15 ~ 20
Drive chainCheck chain slack and alignment. Check that the chain is lubri-
cated properly.P.3-21 ~ 22
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-24 ~ 25
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-25 ~ 27
Front forks and rear shock
absorber assemblyCheck that they operate smoothly and there is no oil leakage. P.3-23 ~ 24
Cables (wires)Check that the clutch and throttle cables move smoothly. Check
that they are not caught when the handlebars are turned or
when the front forks travel up and down.—
Muffler Check that the muffler is tightly mounted and has no cracks. P.4-2
Sprocket Check that the driven sprocket tightening nut is not loose. P.3-20
Lubrication Check for smooth operation. Lubricate if necessary. P.3-28
Bolts and nuts Check the chassis and engine for loose bolts and nuts. —
Lead connectorsCheck that the CDI magneto, CDI unit, and ignition coil are con-
nected tightly.P.1-5

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

3 - 11
INSP
ADJ
VALVE CLEARANCE INSPECTION AND ADJUSTMENT
VALVE CLEARANCE INSPECTION AND
ADJUSTMENT
NOTE:
lThe valve clearance should be adjusted
when the engine is cool to the touch.
lThe piston must be at Top Dead Center
(T.D.C.) on compression stroke to check or
adjust the valve clearance.
1. Remove:
lSeat
lFuel tank
Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section in the CHAPTER 4. Adjustment steps:
lAdjust the pilot air screw.
Refer to “PILOT AIR SCREW ADJUST-
MENT” section.
lTurn the throttle stop screw 1 until the
specified engine idling speed.
To increase idling speed ®
Turn the throttle stop screw 1 in a.
To decrease idling speed ®
Turn the throttle stop screw 1 out b.
Inductive tachometer:
YU-8036-B/90890-03113
Engine idling speed:
1,300 ~ 1,500 r/min
2. Remove:
lSpark plug
lIntake tappet cover 1
lExhaust tappet cover 2
lO-ring
3. Remove:
lTiming mark accessing screw 1
lCrankshaft end accessing screw 2
lO-ring

3 - 13
INSP
ADJ
VALVE CLEARANCE INSPECTION AND ADJUSTMENT
lMeasure the valve clearance.
lIf the clearance is incorrect, repeat above
steps until specified clearance is obtained.
6. Install:
lO-ring 1
lCrankshaft end accessing screw 2
lTiming mark accessing screw 3
NOTE:
Apply the lithium soap base grease on the O-
rings.
New
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
7. Install:
lO-ring 1
lExhaust tappet cover 2
lIntake tappet cover 3
NOTE:
Apply the lithium soap base grease on the O-
rings.
8. Install:
lSpark plug
lFuel tank
lSeat
Refer to “SEAT, FUEL TANK AND
SIDE COVERS” section in the CHAP-
TER 4.
New
T R..18 Nm (1.8 m · kg, 13 ft · lb)
T R..18 Nm (1.8 m · kg, 13 ft · lb)
T R..13 Nm (1.3 m · kg, 9.4 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)

3 - 27
INSP
ADJ
STEERING HEAD INSPECTION AND ADJUSTMENT
T R..
Ring nut (final tightening):
20 Nm (2.0 m • kg, 14 ft • lb)
lCheck the steering stem by turning it lock
to lock. If there is any binding, remove the
steering stem assembly and inspect the
steering bearings.
lInstall the rubber washer 8, upper ring
nut 9 and special washer 0.
NOTE:
lTighten the upper ring nut until it contacts
the rubber washer.
lInsert the special washer pawls into the
slots. If the slots are not aligned, tighten
the upper ring nut for alignment.
lInstall the upper bracket A, steering stem
nut B, cap C, handlebar D, upper han-
dlebar holder E, starter knob nut F and
number plate G.
NOTE:
lThe upper handlebar holder should be
installed with the punched mark a for-
ward.
lInsert the end of fuel breather hose H into
the hole of the starter knob stay.
CAUTION:
First tighten the bolts on the front side of
the handlebar holder, and then tighten
the bolts on the rear side.
T R..
Pinch bolt (upper bracket):
25 Nm (2.5 m • kg, 18 ft • lb)
Steering stem nut:
110 Nm (11.0 m • kg, 80 ft • lb)
Handlebar upper holder:
23 Nm (2.3 m • kg, 17 ft • lb)
Starter knob nut:
1 Nm (0.1 m • kg, 0.7 ft • lb)
Number plate:
7 Nm (0.7 m • kg, 5.1 ft • lb)

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
4

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