2004 YAMAHA YZ125LC brake

2-10
SPECMAINTENANCE SPECIFICATIONS
Part to be tightened Thread size Q'tyT ightening torqueNm m•kg ft•lb
Rear brake master cylinder and frame M 6 ×1.0 2 10 1.0 7.2
Rear brake master cylinder cap M 4 ×0.7 2 2 0.2 1.4
Rear brake hose union bolt (caliper) M10 ×1.25 1 30 3.0 22
Rear brake hose union bolt (master cylinder) M10 ×1.25 1 30 3.0 22
Rear wheel axle and nut M20 ×1.5 1 125 12.5 90
Nipple (spoke) – 72 3 0.3 2.2
Driven sprocket and wheel hub M 8 ×1.25 6 42 4.2 30
Disc cover and rear brake caliper M 6 ×1.0 2 7 0.7 5.1
Protector and rear brake caliper M 6 ×1.0 2 7 0.7 5.1
Chain puller adjust bolt and locknut M 8 ×1.25 2 16 1.6 11
Engine mounting:
Engine and frame (front) M10 ×1.25 1 64 6.4 46
Engine and frame (lower) M10 ×1.25 1 64 6.4 46
Engine bracket and frame M 8 ×1.25 2 34 3.4 24
Engine bracket and engine M 8 ×1.25 1 34 3.4 24
Pivot shaft and nut M16 ×1.5 1 85 8.5 61
Relay arm and swingarm M14 ×1.5 1 80 8.0 58
Relay arm and connecting rod M14 ×1.5 1 80 8.0 58
Connecting rod and frame M14 ×1.5 1 80 8.0 58
Rear shock absorber and frame M10 ×1.25 1 56 5.6 40
Rear shock absorber and relay arm M10 ×1.25 1 53 5.3 38
Rear frame and frame (upper) M 8 ×1.25 1 32 3.2 23
Rear frame and frame (lower) M 8 ×1.25 2 29 2.9 21
Swingarm and brake hose holder M 5 ×0.8 4 1 0.1 0.7
Swingarm and patch M 4 ×0.7 4 2 0.2 1.4
Chain tensioner mounting M 8 ×1.25 2 19 1.9 13
Chain support and swingarm M 6 ×1.0 3 7 0.7 5.1
Seal guard and swingarm M 5 ×0.8 4 6 0.6 4.3
Fuel tank mounting M 6 ×1.0 2 10 1.0 7.2
Fuel tank and fuel cock M 6 ×1.0 2 7 0.7 5.1
Fuel tank and seat set bracket M 6 ×1.0 1 7 0.7 5.1
Fuel tank and hooking screw (fitting band) M 6 ×1.0 1 7 0.7 5.1
Fuel tank and fuel tank bracket M 6 ×1.0 4 7 0.7 5.1
Air scoop mounting M 6 ×1.0 6 4 0.4 2.9
Front fender mounting M 6 ×1.0 4 7 0.7 5.1
Rear fender mounting (front) M 6 ×1.0 2 7 0.7 5.1
Rear fender mounting (rear) M 6 ×1.0 2 12 1.2 8.7
Side cover mounting M 6 ×1.0 2 7 0.7 5.1
Seat mounting M 8 ×1.25 2 19 1.9 13
Number plate M 6 ×1.0 1 7 0.7 5.1
NOTE:

- marked portion shall be checked for torque tightening after break-in or before each race.


 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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2-13
SPECCABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1Brake hose
2Cable guide
3“ENGINE STOP” button lead
4Fuel tank breather hose
5Clamp
6Throttle cable
7Wireharness
8YPVS breather hose
9Radiator breather hose
0CDI magneto lead
q“ENGINE STOP” button lead
connector
wAir vent hose (left)
eOverflow hose
rAir vent hose (right)
tTransmission oil breather hoseAFasten the ground lead
together with the front
installation portion of the
ignition coil.
BPass the throttle cable and
“ENGINE STOP” button lead
into the cable guide. Align
with the cable guide the
front end of the tape on the
throttle cable.
CPass the fuel tank breather
hose between the handlebar
and tension bar, then insert
its end into the hole of the
number plate.
DPass the throttle cable and
“ENGINE STOP” button lead
over the radiator hose.
EClamp the throttle cable,
“ENGINE STOP” button lead
and wireharness to the main
pipe.FPass the wireharness on the
outside of the “ENGINE STOP”
button lead.
GClamp the throttle cable and
wireharness to the main pipe.
HPass the transmission oil
breather hose, air vent hoses
and overflow hose between
the frame and connecting rod.
IPass the radiator breather
hose and YPVS breather hose
outside the engine bracket
and inside the down tube. Then
pass the radiator breather
hose inside the YPVS
breather hose.
JClamp the radiator breather
hose and CDI magneto lead
on the rear of the down-tube.
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2-14
SPECCABLE ROUTING DIAGRAM
KPass the radiater breather
hose and CDI magneto
lead between the frame and
radiator.
LAlign the top of the brake hose
neck with the brake hose
holder bottom.
MPass the brake hose in front
of the axle boss, then fit it
into the hose groove so that
the brake hose does not
contact the nut (wheel axle).
NFit the brake hose into the
guide on the protector.
OPosition each lead at the lower
left of the main tube (frame)
and put the clamp ends within
the area as shown by the
arrow.
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2-16
SPECCABLE ROUTING DIAGRAM
AInstall the brake hose so that its pipe portion
directs as shown and lightly touches the projec-
tion on the caliper.
BPass the brake hose into the brake hose
holders.
CIf the brake hose contacts the spring (rear
shock absorber), correct its twist.
DInstall the brake hose so that its pipe portion
directs as shown and lightly touches the
projection on the master cylinder. 1Master cylinder
2Brake hose holder
3Brake hose
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2-17
SPECCABLE ROUTING DIAGRAM
AInstall the brake hose so that its pipe portion
directs as shown and lightly touches the
projection on the master cylinder.
BPass the “ENGINE STOP” button lead in
the middle of the clutch holder.
CPass the clutch cable in front of the throttle
cable.
DClamp the “ENGINE STOP” button lead to
the handlebar to 3 clicks.
EPass the brake hose in front of the number
plate and through the cable guide.
FCross the clutch cable and throttle cable
over the number plate boss. 1Brake hose
2Master cylinder
3“ENGINE STOP” button lead
4“ENGINE STOP” button
5Throttle cable
6Clutch cable
7Clamp
8Cable guide
5XE-9-30-2B 5/10/03 1:57 PM Page 34

3-2
MAINTENANCE INTERVALS
INSP
ADJ
Item Remarks
COOLING SYSTEM
Check coolant level and leakage
Check radiator cap operation
Replace coolantEvery two years
Inspect hoses
OUTSIDE NUTS AND BOLTS Refer to “STARTING
RetightenAND BREAK-IN” section
in the CHAPTER 1.
AIR FILTER
Clean and lubricateUse foam air-filter oil or
Replaceequivalent oil
FRAME
Clean and inspect
FUEL TANK, COCK
Clean and inspect
BRAKES
Adjust lever position and pedal height
Lubricate pivot point
Check brake disc surface
Check fluid level and leakage
Retighten brake disc bolts, caliper bolts,

master cylinder bolts and union bolts
Replace pads
Replace brake fluidEvery one year
FRONT FORKS
Inspect and adjust
Replace oilSuspension oil “01”
Replace oil seal
FRONT FORK OIL SEAL AND DUST SEAL
Clean and lubeLithium base grease
REAR SHOCK ABSORBER
(After
Inspect and adjustrain ride)
Lube Molybdenum disulfide grease
Retighten
CHAIN GUARD AND ROLLERS
Inspect
SWINGARM
Inspect, lube and retightenMolybdenum disulfide grease
RELAY ARM, CONNECTING ROD
Inspect, lube and retightenMolybdenum disulfide grease
STEERING HEAD
Inspect free play and retighten
Clean and lubeLithium base grease
Replace bearing
TIRE, WHEELS
Inspect air pressure, wheel run-out,

tire wear and spoke looseness
Retighten sprocket bolt
Inspect bearings
Replace bearings
LubricateLithium base grease
THROTTLE, CONTROL CABLE
Check routing and connectionYamaha cable lube or
LubricateSAE 10W-30 motor oil
After
break-
inEvery
raceEvery
thirdEvery
fifthAs re-
quired
3
5XE-9-30-3A 4/28/03 5:55 PM Page 3

3-4
PRE-OPERATION INSPECTION AND MAINTENANCE
INSP
ADJ
EC320000
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
EC321000
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
Coolant Check that coolant is filled up to the radiator filler cap.
Check the cooling system for leakage.P3-5~9
Fuel Check that a fresh mixture of oil and gasoline is filled in
the fuel tank. Check the fuel line for leakage.P1-12
Transmission oil Check that the oil level is correct. Check the crankcase
for leakage.P3-12~14
Gear shifter and clutch Check that gears can be shifted correctly in order and
that the clutch operates smoothly.P3-9
Throttle grip/Housing Check that the throttle grip operation and free play
are correctly adjusted. Lubricate the throttle grip and P3-10~11
housing, if necessary.
Brakes Check the play of front brake and effect of front and
rear brake.P3-17~23
Chain Check chain slack and alignment. Check that the chain
is lubricated properly.P3-24~26
Wheels Check for excessive wear and tire pressure. Check for
loose spokes and have no excessive play.P3-34~35
Steering Check that the handlebar can be turned smoothly and
have no excessive play.P3-35~36
Front forks and Check that they operate smoothly and there is no oil
rear shock absorber leakage.P3-26~33
Cables (wires) Check that the clutch and throttle cables move smooth-
ly. 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.P3-15~16
Sprocket Check that the driven sprocket tightening bolt is
not loose.P3-24
Lubrication Check for smooth operation. Lubricate if necessary. P3-37
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P1-16
Lead connectors Check that the CDI magneto, CDI unit, and ignition coil
are connected tightly.P1-6
Settings Is the machine set suitably for the condition of the
racing course and weather or by taking into account the
P7-1~25
results of test runs before racing? Are inspection and
maintenance completely done?
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3-17
INSP
ADJ
CHASSIS/BRAKE SYSTEM AIR BLEEDING
EC360000
CHASSIS
EC361030
BRAKE SYSTEM AIR BLEEDING
w
Bleed the brake system if:
9The system has been disassembled.
9A brake hose has been loosened or removed.
9The brake fluid is very low.
9The brake operation is faulty.
A dangerous loss of braking performance may
occur if the brake system is not properly bled.
1. Remove:
9Master cylinder cap
9Diaphragm
9Reservoir float (front brake)
9Protector (rear brake)
2. Bleed:
9Brake fluid
ÅFront
ıRear
Air bleeding steps:
a. Add proper brake fluid to the reservoir.
b. Install the diaphragm. Be careful not to
spill any fluid or allow the reservoir to
overflow.
c. Connect the clear plastic tube 2tightly to
the caliper bleed screw 1.
d. Place the other end of the tube into a
container.
e. Slowly apply the brake lever or pedal
several times.
f. Pull the lever in or push down on the ped-
al. Hold the lever or pedal in position.
g. Loosen the bleed screw and allow the
lever or pedal to travel towards its limit.
h. Tighten the bleed screw when the lever
or pedal limit has been reached; then re-
lease the lever or pedal.
i. Repeat steps (e) to (h) until of the air
bubbles have been removed from the
system.
Bleed screw:
6 Nm (0.6 m•kg, 4.3 ft•lb)
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