2001 YAMAHA YZ125LC fuel

2-13
SPECCABLE ROUTING DIAGRAM
EC240000
1Brake hose
2Fuel tank breather hose
3Cable guide
4Clamp
5“ENGINE STOP” button lead
6Throttle cable
7Air vent hose (right)
8Air vent hose (left)
9Transmission oil breather
hose
0Overflow hose
qRadiator breather hose
wCDI magneto lead
eYPVS breather hose
APass the fuel tank breather
hose between the handlebar
and tension bar, then insert
its end into the hole of the
number plate.
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.CClamp the throttle cable and
“ENGINE STOP” button lead
to the frame. With the clamp
ends downward, tighten the
throttle cable to the extent
that it moves smoothly.
DClamp the “ENGINE STOP”
button lead (where there is
no protector), wireharness and
throttle cable all together to the
frame. With the clamp ends
downward, pass the
wireharness on the outer side
of the chassis in relation to the
“ENGINE STOP” button lead.
EPass the air vent hose at
the rear of the throttle cable.
FPass the transmission oil
breather hose, air vent hoses
and overflow hose between
the frame and connecting rod.
GPass the radiator breather
hose and YPVS breather hose
outside the engine bracket
and inside the frame. Then
pass the radiator breather hose inside the YPVS
breather hose.
HClamp the radiater breather
hose and CDI magneto lead
on the rear of the down-tube.
IPass the radiater breather
hose and CDI magneto
lead between the frame and
radiator.
JAlign the top of the brake hose
neck with the brake hose
holder bottom.
KPass 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).
LFit the brake hose into the
guide on the protector.
MPass the throttle cable and
“ENGINE STOP” button lead
over the radiator hose.
NTighten the clamp with its
ends sideways as shown.
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3-2
MAINTENANCE INTERVALS
INSP
ADJ
Item Remarks
COOLING SYSTEM
Check coolant level and leakagell
Check radiator cap operationl
Replace coolantlEvery two years
Inspect hosesl
OUTSIDE NUTS AND BOLTS Refer to “STARTING
RetightenllAND BREAK-IN” section
in the CHAPTER 1.
AIR FILTER
Clean and lubricatellUse foam air-filter oil
Replacel
FRAME
Clean and inspectll
FUEL TANK, COCK
Clean and inspectll
BRAKES
Adjust lever position and pedal heightll
Lubricate pivot pointll
Check brake disc surfacell
Check fluid level and leakagell
Retighten brake disc bolts, caliper bolts,
ll
master cylinder bolts and union bolts
Replace padsl
Replace brake fluidlEvery one year
FRONT FORKS
Inspect and adjustll
Replace oilllSuspension oil “01”
Replace oil seall
FRONT FORK OIL SEAL AND DUST SEAL
Clean and lubellLithium base grease
REAR SHOCK ABSORBER
Inspect and adjustll
Lube ll
Molybdenum disulfide grease
Retightenll
CHAIN GUARD AND ROLLERS
Inspectll
SWINGARM
Inspect and retightenll
RELAY ARM, CONNECTING ROD
Inspect and lubellMolybdenum disulfide grease
STEERING HEAD
Inspect free play and retightenll
Clean and lubelLithium base grease
Replace bearingl
TIRE, WHEELS
Inspect air pressure, wheel run-out,
ll
tire wear and spoke looseness
Retighten sprocket boltll
Inspect bearingsl
Replace bearingsl
LubricatelLithium base grease
THROTTLE, CONTROL CABLE
Check routing and connectionllYamaha cable lube or
LubricatellSAE 10W-30 motor oil
After
break-
inEvery
raceEvery
thirdEvery
fifthAs re-
quired
3
5MV-9-30-3A 6/19/00 1:52 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
P7-1~24
results of test runs before racing? Are inspection and
maintenance completely done?
5MV-9-30-3A 6/19/00 1:52 PM Page 14

3-36
STEERING HEAD INSPECTION AND ADJUSTMENT
INSP
ADJ
9Loosen the ring nut one turn.
9Retighten the ring nut using the ring nut
wrench.
w
Avoid over-tightening.
9Check the steering shaft by turning it lock to
lock. If there is any binding, remove the
steering shaft assembly and inspect the
steering bearings.
9Install the handle crown 5, steering shaft
nut 6, handlebar 7, handlebar holder 8
and number plate 9.
NOTE:
9The upper handlebar holder should be
installed with the punched mark aforward.
9Insert the end of fuel breather hose 0into
the hole of the number plate.
cC
First tighten the bolts on the front side of
the handlebar holder, and then tighten the
bolts on the rear side.
Ring nut wrench:
YU-33975/90890-01403
Ring nut (initial tightening):
38 Nm (3.8 m•kg, 27ft•lb)
Steering shaft nut:
145 Nm (14.5 m•kg, 105 t•lb)
Handlebar upper holder:
28 Nm (2.8 m•kg, 20 ft•lb)
Pinch bolt (handle crown):
23 Nm (2.3 m•kg, 17 ft•lb)
Number plate:
7 Nm (0.7 m•kg, 5.1 ft•lb)
Ring nut (final tightening):
7 Nm (0.7 m•kg, 5.1 ft•lb)
5MV-9-30-3B 6/19/00 1:49 PM Page 36

4-1
ENGSEAT, FUEL TANK AND SIDE COVERS
EC400000
ENGINE
EC4R0000
SEAT, FUEL TANK AND SIDE COVERS
Extent of removal Order Part name Q’ty Remarks
SEAT, FUEL TANK AND SIDE
COVERS REMOVAL
Preparation for Turn the fuel cock to “OFF”.
removal Disconnect the fuel hose.
1 Seat 1
2 Air scoop (left and right) 2
3 Fitting band 1 Remove on fuel tank side.
4 Bolt (fuel tank) 2
5 Fuel tank 1
6 Side cover (left) 1
Refer to “REMOVAL POINTS”.
7 Side cover (right) 1
8 Number plate 1
1
4
3
Extent of removal:1Seat removal2Fuel tank removal
3Side covers removal4Number plate removal
2
ü
ý
þ ü
ý
þ3
4
7 Nm (0.7 m•kg, 5.1 ft•lb)
3 Nm (0.3 m•kg, 2.2 ft•lb)
3 Nm (0.3 m•kg, 2.2 ft•lb)
3 Nm (0.3 m•kg, 2.2 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
5MV-9-30-4A 6/19/00 1:47 PM Page 2

4-2
ENGSEAT, FUEL TANK AND SIDE COVERS
EC4R3000
REMOVAL POINTS
EC413101
Side cover
1. Remove:
9Side cover (left and right) 1
cC
Be sure to remove the seat before remov-
ing the side cover. If you remove the side
cover with force without removing the seat,
the panel 2 2
(on the inside) may contact
the air cleaner case and come off.
5MV-9-30-4A 6/19/00 1:47 PM Page 4

4-3
ENGEXHAUST PIPE AND SILENCER
EC4S0000
EXHAUST PIPE AND SILENCER
Extent of removal Order Part name Q’ty Remarks
EXHAUST PIPE AND
SILENCER REMOVAL
Preparation for Side cover (right) Refer to “SEAT, FUEL TANK AND
removal SIDE COVERS” section.
1 Bolt (silencer) 2
2 Silencer 1
3 Tension spring 2
4 Bolt (exhaust pipe) 2
5 Exhaust pipe 1
1
Extent of removal:1Silencer removal2Exhaust pipe removal
2
12 Nm (1.2 m•kg, 8.7 ft•lb)
12 Nm (1.2 m•kg, 8.7 ft•lb)
12 Nm (1.2 m•kg, 8.7 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
5MV-9-30-4A 6/19/00 1:47 PM Page 6

4-4
ENGRADIATOR
Extent of removal Order Part name Q’ty Remarks
RADIATOR REMOVAL
Preparation for Drain the coolant.
Refer to “COOLANT REPLACEMENT“
removal section in the CHAPTER 3.
Seat and fuel tank Refer to “SEAT, FUEL TANK AND
SIDE COVERS” section.
1 Panel 2 Refer to ”REMOVAL POINTS“.
2 Clamp (radiator hose 1, 3) 2 Only loosening.
3 Radiator hose 2 1
4 Radiator (left) 1
5 Radiator hose 4 1
6 Radiator (right) 1
7 Radiator hose 1 1
8 Radiator hose 3 1
9 Radiator breather hose 1
EC450001
RADIATOR
Extent of removal:1Radiator removal
1
1 Nm (0.1 m•kg, 0.7 ft•lb)
1 Nm (0.1 m•kg, 0.7 ft•lb)
5MV-9-30-4A 6/19/00 1:47 PM Page 8