2002 YAMAHA YZ125LC radiator cap

KAPITEL 4
MOTOR
SITZ, KRAFTSTOFFTANK UND
SEITENDECKEL.........................................4-1
AUSPUFFROHR UND
SCHALLDÄMPFER....................................4-3
KÜHLER......................................................4-4
VERGASER UND ZUNGENVENTIL...........4-7
ZYLINDERKOPF, ZYLINDER UND
KOLBEN...................................................4-17
KUPPLUNG UND
PRIMÄRABTRIEBSZAHNRAD................4-30
KICKSTARTERWELLE, SCHALTWELLE
UND PRIMÄRANTRIEBSZAHNRAD.......4-38
YPVS REGLER.........................................4-46
WASSERPUMPE......................................4-49
CDI-MAGNETZÜNDER.............................4-53
AUSBAU DES MOTORS..........................4-57
KURBELGEHÄUSE UND
KURBELWELLE.......................................4-62
GETRIEBE, SCHALTNOCKE UND
SCHALTGABEL.......................................4-69
KAPITEL 5
FAHRGESTELL
VORDERRAD UND HINTERRAD..............5-1
VORDERRADBREMSE UND
HINTERRADBREMSE..............................5-10
VORDERRADGABEL...............................5-27
LENKSTANGE..........................................5-40
LENKUNG.................................................5-47
HINTERRADSCHWINGE..........................5-52
HINTERRAD-STOSSDÄMPFER..............5-59
CHAPITRE 4
MOTEUR
SELLE, RESERVOIR A ESSENCE
ET COUVERCLES LATERAUX..............4-1
TUYAU D’ECHAPPEMENT ET
SILENCIEUX..............................................4-3
RADIATEUR...............................................4-4
CARBURATEUR ET
SOUPAPE FLEXIBLE...............................4-7
CULASSE, CYLINDRE ET PISTON.....4-17
EMBRAYAGE ET PIGNON
MENE PRIMAIRE....................................4-30
AXE DE DEMARREUR AU PIED,
ARBRE DE SELECTEUR ET PIGNON
DE TRANSMISSION PRIMAIRE..........4-38
REGULATEUR YPVS..............................4-46
POMPE A EAU.........................................4-49
MAGNETO CDI........................................4-53
DEPOSE DU MOTEUR...........................4-57
CARTER ET VILEBREQUIN.................4-62
BOITE A VITESSES, BARILLET
DE SELECTEUR ET FOURCHETTE...4-69
CHAPITRE 5
PARTIE CYCLE
ROUE AVANT ET ROUE ARRIERE......5-1
FREIN AVANT ET FREIN ARRIERE..5-10
FOURCHE AVANT..................................5-27
GUIDON.....................................................5-40
DIRECTION..............................................5-47
BRAS OSCILLANT..................................5-52
AMORTISSEUR ARRIERE....................5-59
CAPITOLO 4
MOTORE
SELLA, SERBATOIO DEL
CARBURANTE E COPERTURE
LATERALI..................................................4-1
TUBO DI SCARICO E
SILENZIATORE.........................................4-3
RADIATORE...............................................4-4
CARBURATORE E VALVOLA A
LAMELLA...................................................4-7
TESTA CILINDRO, CILINDRO E
PISTONE....................................................4-17
FRIZIONE E INGRANAGGIO
CONDOTTO PRIMARIO........................4-30
PEDIVELLA, ALBERO DEL
CAMBIO E INGRANAGGIO
CONDUTTORE PRIMARIO...................4-38
REGOLATORE YPVS.............................4-46
POMPA DELL’ACQUA...........................4-49
MAGNETE CDI........................................4-53
RIMOZIONE DEL MOTORE.................4-57
CARTER E ALBERO A GOMITI..........4-62
TRASMISSIONE, CAMMA DEL
CAMBIO E FORCELLA DEL
CAMBIO....................................................4-69
CAPITOLO 5
TELAIO
RUOTA ANTERIORE E RUOTA
POSTERIORE.............................................5-1
FRENO ANTERIORE E FRENO
POSTERIORE ..........................................5-10
FORCELLA ANTERIORE......................5-27
MANUBRIO...............................................5-40
STERZO.....................................................5-47
FORCELLONE OSCILLANTE..............5-52
AMMORTIZZATORE POSTERIORE..5-59
5NY-9-30-0 5/23/01 8:01 PM Page 21

1-1
GEN
INFO
DESCRIPTION
EC100000
GENERAL INFORMATION
EC110000
DESCRIPTION
1Clutch lever
2”ENGINE STOP” button
3Front brake lever
4Throttle grip
5Radiator cap
6Fuel tank cap
7Kick starter
8Fuel tank
9Radiator
0Coolant drain bolt
qCheck bolt (Transmission oil level)
wRear brake pedal
eValve joint
rFuel cock
tAir cleaner
yDrive chain
uShift pedal
iStarter knob
oFront fork
NOTE:
9The machine you have purchased may differ
slightly from those shown in the following.
9Designs and specifications are subject to
change without notice.
1
5NY-9-30-1A 5/24/01 7:32 PM Page 2

1-8
GEN
INFO
SPECIAL TOOLS
Part number Tool name / How to use IIIustration
YU-24460-01, 90890-01325Radiator cap testerYU-24460-01 90890-01325
YU-33984, 90890-01352 AdapterYU-33984 90890-01352
These tools are used for checking the cooling
system.
YU-33975, 90890-01403 Ring nut wrench
YU-33975 90890-01403
This tool is used when tighten the steering ring nut
to specification.
YM-1423, 90890-01423 Damper rod holder
YM-1423 90890-01423
Use this tool to remove and install the damper rod.
YM-01442, 90890-01442 Fork seal driver
YM-01442 90890-01442
This tool is used when install the fork oil seal.
YU-3112-C, Yamaha pocket tester
YU-3112-C 90890-03112
90890-03112
Use this tool to inspect the coil resistance,
output voltage and amperage.
YM-91042, 90890-04086 Clutch holding tool
YM-91042 90890-04086
This tool is used to hold the clutch when removing
or installing the clutch boss securing nut.
YM-34487 Dynamic spark tester
YM-34487 90890-06754
90890-06754 Ignition checker
This instrument is necessary for checking the igni-
tion system components.
ACC-QUICK-GS-KT Quick gasket
®ACC-QUICK-GS-KT 90890-85505
90890-85505 YAMAHA Bond No. 1215
This sealant (Bond) is used for crankcase mating
surface, etc.
5NY-9-30-1A 5/24/01 7:33 PM Page 15

2-4
SPECMAINTENANCE SPECIFICATIONS
Item Standard Limit
Transmission:
Main axle deflection limit…
0.01 mm (0.0004 in)
Drive axle deflection limit…
0.01 mm (0.0004 in)
Shifter:
Shifting type Cam drum and guide bar…
Guide bar bending limit…
0.05 mm (0.0020 in)
Kick starter type: Kick and mesh type…
Kick clip friction force P=0.8~1.2 kg (1.8~2.6 lb)…
Air filter oil grade (oiled filter):Foam-air-filter oil or engine mixing oil…
Carburetor: USA, CDN, ZA
EUROPE
AUS, NZ
Type/Manufacturer TMXχ
38SS←
/MIKUNI
I.D. mark 5NY1 00 5NY2 10…
Main jet (M.J.) #420 #430…
Jet needle-clip position (J.N.) 6CHY5-79-3 6CHY5-77-3…
Cutaway (C.A.) 5.75←…
Pilot jet (P.J.) #30←…
Pilot air screw (P.A.S.) 2-1/2 1-3/4…
Valve seat size (V.S.)
ø3.8 mm (0.15 in)←…
Starter jet (G.S.) #80←…
Fuel level (F.L.) 9.5~10.5 mm 11.5~12.5 mm
(0.37~0.41 in) (0.45~0.49 in)
Reed valve:
Thickness* 0.42 mm (0.017 in)…
Valve stopper height 8.2~8.6 mm (0.323~0.339 in)…
Valve bending limit…
0.2 mm (0.008 in)
Cooling:
Radiator core size:
Width 107.8 mm (4.24 in)…
Height (left) 240 mm (9.45 in)…
(right) 220 mm (8.66 in)…
Thickness 32 mm (1.26 in)…
Radiator cap opening pressure 95~125 kPa…
(0.95~1.25 kg/cm
2, 13.5~17.8 psi)
Radiator capacity (total) 0.57 L (0.50 Imp qt, 0.60 US qt)…
Water pump:
Type Single-suction centrifugal pump…
5NY-9-30-2A 5/24/01 8:03 PM Page 5

2-4
SPECSPECIFICHE DI MANUTENZIONE
Voce Valore normale Limite
Trasmissione:
Limite di inflessione dell’asse principale…
0,01 mm (0,0004 in)
Limite di inflessione dell’asse motore…
0,01 mm (0,0004 in)
Cambio:
Tipo di cambio
Tamburo a camme e guida di scorrimento…
Limite di flessione della guida di scorrimento…
0,05 mm (0,0020 in)
Tipo di pedivella della messa in moto: Tipo a pedivella e ingranamento…
Forza di attrito della staffa P=0,8~1,2 kg (1,8~2,6 lb) …
della pedivella
Qualità dell’olio del filtro dell’aria Olio per filtro dell’aria in schiuma …
(filtro oliato): oppure olio per miscela per motori
Carburatore: USA, CDN, ZA,
EUROPA
AUS, NZ
Tipo/Costruttore TMX
χ38SS←
/MIKUNI
Marchio ID 5NY1 00 5NY2 10…
Getto principale (M.J.) No. 420 No. 430…
Posizione della staffa dell’ago di getto(J.N.) 6CHY5-79-3 6CHY5-77-3…
Sezione (C.A.) 5,75←…
Getto pilota (P.J.) No. 30←…
Vite dell’aria pilota (P.A.S.) 2-1/2 1-3/4…
Dimensioni della sede della valvola(V.S.)ø3,8 mm (0,15 in)←…
Getto avviamento (G.S.) No. 80←…
Livello del carburante (F.L.) 9,5~10,5 mm 11,5~12,5 mm
(0,37~0,41 in) (0,45~0,49 in)
Valvola a lamella:
Spessore* 0,42 mm (0,017 in)…
Altezza arresto valvola 8,2~8,6 mm (0,323~0,339 in)…
Limite di flessione della valvola … 0,2 mm (0,008 in)
Raffreddamento:
Dimensioni dell’anima del radiatore:
Larghezza 107,8 mm (4,24 in)…
Altezza (sinistra) 240 mm (9,45 in)…
(destra) 220 mm (8,66 in)…
Spessore 32 mm (1,26 in)…
Pressione di apertura del tappo 95~125 kPa…
del radiatore (0,95~1,25 kg/cm
2, 13,5~17,8 psi)
Capacità del radiatore (totale) 0,57 L (0,50 Imp qt, 0,60 US qt)…
Pompa dell’acqua:
Tipo
Pompa centrifuga ad aspirazione singola…
5NY-9-30-2B 5/23/01 8:03 PM Page 17

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
Replace
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
5NY-9-30-3A 5/23/01 8:24 PM Page 3

3-2
INTERVALLI DI MANUTENZIONE
INSP
ADJ
IMPIANTO DI RAFFREDDAMENTO
Controllo livello e perdite di liquido
66refrigerante
Controllo funzionamento del tappo
del radiatore
6
Sostituzione del liquido refrigerante6
Ispezione dei tubi flessibili6
DADI E VITI ESTERNI
Riserraggio
66
FILTRO DELL’ARIA
Pulitura e lubrificazione
66
Sostituzione6
TELAIO
Pulitura e ispezione
66
SERBATOIO, RUBINETTO DEL
CARBURANTE
Pulitura e ispezione
66
FRENI
Regolazione posizione della leva e
66altezza del pedale
Lubrificazione punto di snodo
66
Controllo superficie del disco del freno66
Controllo livello e perdite di liquido66
Riserraggio bulloni del disco del
freno, bulloni della pinza, bulloni del
66
cilindro principale e bulloni di unione
Sostituzione pastiglie
6
Sostituzione liquido per freni6
FORCELLE ANTERIORI
Ispezione e regolazione
66
Sostituzione dell’olio66
Sostituzione del paraolio6
PARAOLIO E PARAPOLVERE
DELLA FORCELLA ANTERIORE
Pulitura e lubrificazione
66
AMMORTIZZATORE POSTERIORE
Ispezione e regolazione
66
Lubrificazione 66
Riserraggio66
COPRICATENA E RULLI PER
CATENA
Ispezione
66
FORCELLONE OSCILLANTE
Ispezione, lubrificazione e riserraggio
66
BRACCIO DI RINVIO, LEVA
DI RINVIO
Ispezione, lubrificazione e riserraggio
66
TESTA DI STERZO
Ispezione gioco libero e riserraggio
66
Pulitura e lubrificazione6
Sostituzione del cuscinetto6
Ogni due anni
Consultare la sezione
“AVVIAMENTO E
RODAGGIO” al CAPITOLO 1.
Usare olio per filtri dell’aria
in schiuma
Ogni anno
Olio per sospensioni “01”
Grasso a base di litio
Grasso a base di bisolfuro di
molibdeno
Grasso a base di bisolfuro di
molibdeno
Grasso a base di bisolfuro di
molibdeno
Grasso a base di litio Dopo il Ogni OgniIn base
Voce
rodaggiogaraOgni
cinquealle Osservazioninecessità
(Dopo un per-
corso sotto la
pioggia)
5NY-9-30-3A 5/23/01 8:24 PM Page 12

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?
5NY-9-30-3A 5/23/01 8:24 PM Page 14