2003 YAMAHA TTR125 steering

SPEC
2 - 21
MAINTENANCE SPECIFICATIONS
NOTE:
1. First, tighten the ring nut approximately 38 Nm (3.8 m • kg, 27 ft • lb) by using the ring nut
wrench and turn the steering right and left a few times; then loosen the ring nut one turn.
2. Retighten the ring nut 20 Nm (2.0 m • kg, 14 ft • lb). Part to be tightened Thread size Q’tyTightening torque
Nm m•kg ft•lb
Upper bracket and inner tube M8 × 1.25 2 25 2.5 18
Lower bracket and inner tube M10 × 1.25 2 60 6.0 43
Upper bracket and steering stem M22 × 1.0 1 110 11.0 80
Handlebar upper holder and upper bracket M8 × 1.25 4 23 2.3 17
Steering stem and ring nut M25 × 1.0 1 Refer to NOTE.
Front fork and cap bolt M25 × 1.0 2 23 2.3 17
Front fork and damper rod M10 × 1.0 2 23 2.3 17
Front fork and brake hose holder M6 × 1.0 2 7 0.7 5.1
Number plate M6 × 1.0 1 7 0.7 5.1
Starter knob M11 × 1.25 1 1 0.1 0.7
Starter knob stay M6 × 1.0 2 10 1.0 7.2
Grip cap upper and lower M5 × 0.8 2 4 0.4 2.9
Throttle cable cap M4 × 0.7 2 2 0.2 1.4
Front brake master cylinder M6 × 1.0 2 9 0.9 6.5
Front brake master cylinder cap M4 × 0.7 2 2 0.2 1.4
Brake lever mounting (bolt) M6 × 1.0 1 7 0.7 5.1
Brake lever mounting (nut) M6 × 1.0 1 7 0.7 5.1
Brake lever adjuster and locknut M6 × 0.75 1 4 0.4 2.9
Clutch lever mounting (bolt) M6 × 1.0 1 7 0.7 5.1
Clutch lever mounting (nut) M6 × 1.0 1 7 0.7 5.1
Clutch lever holder M5 × 0.8 2 4 0.4 2.9
Front brake master cylinder and joint M10 × 1.25 1 26 2.6 19
Front brake hose and joint M10 × 1.25 1 14 1.4 10
Front brake hose union bolt M10 × 1.25 1 26 2.6 19
Front brake caliper and front fork M8 × 1.25 2 30 3.0 22
Brake caliper support bolt M8 × 1.25 1 22 2.2 16
Front brake caliper and bleed screw M7 × 1.0 1 6 0.6 4.3
Front wheel axle and axle nut M12 × 1.25 1 45 4.5 32
Front brake disc and wheel hub M6 × 1.0 4 12 1.2 8.7
Rear wheel axle and axle nut M12 × 1.25 1 60 6.0 43
Rear brake camshaft lever and camshaft M6 × 1.0 1 10 1.0 7.2
Brake pedal mounting M10 × 1.25 1 30 3.0 22
Brake pedal position locknut M6 × 1.0 1 7 0.7 5.1
Front wheel nipple (spoke)—36 2 0.2 1.4
Rear wheel nipple (spoke)—36 3 0.3 2.2

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
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 - 25
INSP
ADJSPOKES INSPECTION AND TIGHTENING/WHEEL INSPECTION/
STEERING HEAD INSPECTION AND ADJUSTMENT
SPOKES INSPECTION AND TIGHTENING
1. Inspect:
Spokes 1
Bend/damage → Replace.
Loose spoke → Retighten.
2. Tighten:
Spokes
NOTE:
Be sure to retighten these spokes before and
after break-in. After a practice check spokes
for looseness.
T R..Front 2 Nm (0.2 m · kg, 1.4 ft · lb)
Rear 3 Nm (0.3 m · kg, 2.2 ft · lb)
EC36T000
WHEEL INSPECTION
1. Inspect:
Wheel runout
Elevate the wheel and turn it.
Abnormal runout → Replace.
2. Inspect:
Bearing free play
Exist play → Replace.
STEERING HEAD INSPECTION AND
ADJUSTMENT
1. Elevate the front wheel by placing a suit-
able stand under the engine.
2. Check:
Steering shaft
Grasp the bottom of the forks and gen-
tly rock the fork assembly back and
forth.
Free play → Adjust steering head.

3 - 26
INSP
ADJ
STEERING HEAD INSPECTION AND ADJUSTMENT
3. Check:
Steering smooth action
Turn the handlebar lock to lock.
Unsmooth action → Adjust steering ring
nut.
4. Adjust:
Steering ring nut
Steering ring nut adjustment steps:
Remove the number plate and starter
knob.
Remove the handlebar and upper bracket.
Remove the special washer 1
Remove the upper ring nut 2, and rubber
washer 3.
Loosen the lower ring nut 4 using the
steering nut wrench 5.
Steering nut wrench:
YU-33975/90890-01403
Tighten the lower ring nut 6 using steer-
ing nut wrench 7 and turn the steering
right and left a few times.
Steering nut wrench:
YU-33975/90890-01403
T R..
Lower ring nut (initial tightening):
38 Nm (3.8 m • kg, 27 ft • lb)
Loosen the lower ring nut one turn.
Retighten the lower ring nut using the
steering nut wrench.
NOTE:
Set the torque wrench to the steering nut
wrench so that they form a right angle.
WARNING
Avoid over-tightening.

3 - 27
INSP
ADJ
STEERING HEAD INSPECTION AND ADJUSTMENT
T R..
Ring nut (final tightening):
20 Nm (2.0 m • kg, 14 ft • lb)
Check the steering stem by turning it lock
to lock. If there is any binding, remove the
steering stem assembly and inspect the
steering bearings.
Install the rubber washer 8, upper ring
nut 9 and special washer 0.
NOTE:
Tighten the upper ring nut until it contacts
the rubber washer.
Insert the special washer pawls into the
slots. If the slots are not aligned, tighten
the upper ring nut for alignment.
Install 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:
The upper handlebar holder should be
installed with the punched mark a for-
ward.
Insert 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)

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CHASSTEERING
EC560000
STEERING
Extent of removal:1 Lower bracket removal2 Bearing removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalSTEERING REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is nodanger of it falling over.
Front forks Refer to “FRONT FORK” section.
Handlebar Refer to “HANDLEBAR” section.
Front fender
1 Steering stem nut 1
2 Upper bracket 1
3 Special washer 1
4 Upper ring nut 1
Use special tool.
Refer to “REMOVAL POINTS”. 5 Rubber washer 1
6 Lower ring nut 1
7 Lower bracket 1
8Bearing cover
1
21

5 - 50
CHASSTEERING
Extent of removal Order Part name Q’ty Remarks
9 Bearing inner race (upper) 1
10 Bearing (upper) 1
11 Bearing outer race (upper) 1
Refer to “REMOVAL POINTS”.
12 Bearing outer race (lower) 1
13Bearing (lower)
1Refer to “REMOVAL POINTS”.
2