2002 YAMAHA YZ125LC oil change

4-50
ENGWATER PUMP
EC4G3000
REMOVAL POINTS
EC4G3110
Impeller shaft
1. Remove:
9Impeller 1
9Plain washer 2
9Impeller shaft 3
NOTE:
Hold the impeller shaft on its width across the
flats awith spanners, etc. and remove the im-
peller.
EC4G3210
Oil seal
NOTE:
It is not necessary to disassemble the water
pump, unless there is an abnormality such as
excessive change in coolant level, discoloration
of coolant, or milky transmission oil.
1. Remove:
9Bearing 1
2. Remove:
9Oil seal 1
EC4G4000
INSPECTIONEC444200
Impeller shaft
1. Inspect:
9Impeller shaft 1
Bend/Wear/Damage Replace.
Fur deposits Clean.
5NY-9-30-4C 5/23/01 8:56 PM Page 26

5-3
CHAS
ROUE AVANT ET ROUE ARRIERE
VORDERRAD UND HINTERRAD
RUOTA ANTERIORE E RUOTA POSTERIORE
AUSBAUPUNKTE
Hinterrad
1. Ausbauen:
9Rad 1
HINWEIS:
Das Rad nach vorne stoßen und die
Antriebskette 2abnehmen.
Radlager (wenn erforderlich)
1. Ausbauen:
9Lager 1
HINWEIS:
Das Lager unter Verwendung einer
allgemeinen Lager-Abziehvorrichtung
2ausbauen.
INSPEKTION
Rad
1. Messen:
9Felgenschlag
Außerhalb des Grenzwertes
Reparieren/Erneuern.
2. Prüfen:
9Lager
Den inneren Laufring mit
einem Finger drehen.
Rauhe Stellen/Freßspuren
Erneuern.
HINWEIS:
Die Lager, die Öldichtung und die
Radhülse als Satz erneuern.
POINTS DE DEPOSE
Roue arrière
1. Déposer:
9Roue 1
N.B.:
Pousser la roue vers l’avant et déposer
la chaîne de transmission 2.
Roulement de roue (si nécessaire)
1. Déposer:
9Roulement 1
N.B.:
Déposer le roulement en utilisant un
arrache-roulement courant 2.
VERIFICATION
Roue
1. Mesure:
9Voile de roue
Hors limiteRéparer/Changer.
2. Examiner:
9Roulement
Faire tourner la bague intérieure
avec le doigt.
Point dur/grippage’Changer.
N.B.:
Changer les roulements, la bague
d’étanchéité et la collerette de roue
comme un ensemble.
IC593000PUNTI DI RIMOZIONE
IC523101
Ruota posteriore
1. Togliere:
9Ruota 1
NOTA:
Spingere in avanti la ruota e togliere la
catena di trasmissione 2.
IC513201
Cuscinetto della ruota (se necessario)
1. Togliere:
9Cuscinetto 1
NOTA:
Togliere il cuscinetto usando un estrat-
tore generico per cuscinetti 2.
IC594000
ISPEZIONE
IC514100
Ruota
1. Misurare:
9Scentratura della ruota
Fuori limite
Ripararla/Sostituirla.
2. Ispezionare:
9Cuscinetto
Ruotare l’anello interno con un
dito.
Ruvidità/Grippaggio
Sostituir-
lo.
NOTA:
Sostituire i cuscinetti, il paraolio e il
bordino della ruota come set.
Limite de voile de la roue:
Radial 1 1
: 2,0 mm
(0,08 in)
Latéral 2 2
: 2,0 mm
(0,08 in)
Limite di scentratura
della ruota:
Radiale 1 1
: 2,0 mm
(0,08 in)
Laterale 2 2
: 2,0 mm
(0,08 in)
Felgen-Verschleißgrenze:Senkrecht 1 1
: 2,0 mm
(0,08 in)
Seitlich 2 2
: 2,0 mm
(0,08 in)
5NY-9-30-5A 5/23/01 9:00 PM Page 7

5-4
CHAS
ROUE AVANT ET ROUE ARRIERE
VORDERRAD UND HINTERRAD
RUOTA ANTERIORE E RUOTA POSTERIORE
Disque de frein
1. Mesurer:
9Déflexion de disque de frein
(uniquement le disque de frein
arrière)
Utiliser le comparateur 1.
Hors spécificationExaminer le
voile de roue.
Si le voile de la roue est normal,
changer le disque de frein.
2. Mesurer:
9Epaisseur de disque de frein a
Hors limiteChanger.
Radachse
1. Messen:
9Radachsenbiegung
Abweichung von Spezifikation
Erneuern.
Die Meßuhr 1verwenden.
HINWEIS:
Der Biegewert entpricht der Hälfte der
Meßuhranzeige.
W
Niemals versuchen, eine verbogene
Achse geradezubiegen.
Axe de roue
1. Mesurer:
9Les flexions de l’axe de roue
Hors-spécification Changer.
Utiliser le comparateur 1.
N.B.:
La valeur de flexion est égale à la moi-
tié de la lecture du comparateur.
XG
Ne jamais tenter de redresser un axe
tordu.
IC514200
Asse della ruota
1. Misurare:
9Curvature dell’asse della ruota
Fuori specificaSostituirlo.
Usare il comparatore 1.
NOTA:
Il valore di curvatura equivale a metà
del valore letto dal comparatore.
T
Non tentare di raddrizzare un asse
piegato.
Limite de torsion de l’axe
de roue:
0,5 mm (0,020 in)
Limite d’usure de disque:
Standard Avant3,0 mm (0,12 in) 2,5 mm (0,10 in)
Arrière 4,0 mm (0,16 in) 3,5 mm (0,14 in)
IC594200
Disco del freno
1. Misurare:
9Inflessione del disco del freno
(soltanto il disco del freno
posteriore)
Usare il comparatore 1.
Fuori specificaIspezionare la
scentratura della ruota.
Se la scentratura della ruota è in
buone condizioni, sostituire il
disco del freno.
2. Misurare:
9Spessore del disco del freno a
Fuori limiteSostituirlo.
Limite di curvatura
dell’asse della ruota:
0,5 mm (0,020 in)
Limite di usura del disco
Valore normaleAnteriore3,0 mm (0,12 in) 2,5 mm (0,10 in)Posteriore4,0 mm (0,16 in) 3,5 mm (0,14 in)
Bremsscheibe
1. Messen:
9Bremsscheibenschlag (Nur
Hinterrad-Bremsscheibe)
Die Meßuhr 1verwenden.
Abweichung von Spezifikation
Schlag der Felge prüfen.
Falls der Felgenschlag inner-
halb des zulässigen Bereiches
liegt, die Bremsscheibe erneu-
ern.
2. Messen:
9Bremsscheibendicke a
Außerhalb des Grenzwertes
Erneuern.
Radachse-durchbie-
guhgsgrenze:
0,5 mm (0,020 in)
Bremsscheibe-
Verschleißgrenze:
Standard
Vorne3,0 mm (0,12 in) 2,5 mm (0,10 in)
Hinten 4,0 mm (0,16 in) 3,5 mm (0,14 in)
Limite de déflection de
disque:
Standard
Arrière—0,15 mm (0,006 in)
Bremsscheiben-
Schlaggrenze:
Standard
Hinten —0,15 mm (0,006 in)
Limite di inflessione del
disco:
Valore normalePosteriore—0,15 mm (0,006 in)
5NY-9-30-5A 5/23/01 9:00 PM Page 9

7-12
TUNSETTING
EC71M001
Change of the heat range of spark plugs
Judging from the discoloration of spark plugs, if
they are found improper, it can be corrected by
the following two methods; changing carburetor
settings and changing the heat range of spark
plug.
9In principle, it is advisable to first use spark
plugs of standard heat range, and judging from
the discoloration of spark plugs, adjust carbure-
tor settings.
9If the calibration No. of the main jet must be
changed by ±30, it is advisable to change the
heat range of spark plugs and newly select the
proper main jet.
NOTE:
9When checking the discoloration of spark
plugs, be sure to stop the engine immediately
after a run and check.
9Avoid racing.
9When changing the heat range of spark plugs,
never attempt to change it more than ±1 rank.
9When using spark plugs other than standard,
make sure of the difference in heat range and
find the equivalent to the standard.
9Note that even if the discoloration seems prop-
er, it may slightly vary with the spark plug
maker and oil in use.
Standard spark plug BR9EG/NGK
5NY-9-30-7A 5/23/01 9:19 PM Page 32

7-15
TUNSETTING
EC722011
Front fork setting
The front fork setting should be made depending
on the rider’s feeling of an actual run and the cir-
cuit conditions.
The front fork setting includes the following three
factors:
1. Setting of air spring characteristics
9Change the fork oil level.
2. Setting of spring preload
9Change the spring.
9Install the adjustment washer.
3. Setting of damping force
9Change the compression damping.
9Change the rebound damping.
The spring acts on the load and the damp-
ing force acts on the cushion travel speed.
EC723001
Change in level and characteristics of fork oil
Damping characteristic near the final stroke can
be changed by changing the fork oil amount.
cC
Adjust the oil level in 5 mm (0.2 in) incre-
ments or decrements. Too low oil level
causes the front fork to produce a noise at
full rebound or the rider to feel some pres-
sure on his hands or body. Alternatively,
too high oil level will develop unexpectedly
early oil lock with the consequent shorter
front fork travel and deteriorated perfor-
mance an characteristics. Therefore, adjust
the front fork within the specified range.
åAir spring characteristics in relation to oil level
change
∫Load
çStroke
1Max. oil level
2Standard oil level
3Min. oil level
Standard oil level:
135 mm (5.31 in)
Extent of adjustment:
80~150 mm (3.15~5.91 in)
From top of outer tube with
inner tube and damper rod fully
compressed without spring.
A
5NY-9-30-7B 5/23/01 9:22 PM Page 6

7-23
TUNSETTING
EC72H010
Suspension setting
9Front fork
NOTE:
9If any of the following symptoms is experienced with the standard position as the base, make reset-
ting by reference to the adjustment procedure given in the same chart.
9Before any change, set the rear shock absorber sunken length to the standard figure 90~100 mm
(3.5~3.9 in).
Section
Symptom
JumpLarge
Medium Small Check Adjust
gap gap gap
Compression damping Turn adjuster counterclockwise (about 2 clicks)
Stiff over entire to decrease damping.
range111Oil level (oil amount) Decrease oil level by about 5~10 mm (0.2~0.4
in).
Spring Replace with soft spring.
Unsmooth Outer tube Check for any bends, dents, and other notice-
movement over 1111Inner tube able scars, etc. If any, replace affected parts.
entire range
Under bracket tightening Retighten to specified torque.
torque
Poor initial Rebound damping Turn adjuster counterclockwise (about 2 clicks)
movement1to decrease damping.
Oil seal Apply grease in oil seal wall.
Compression damping Turn adjuster clockwise (about 2 clicks) to in-
Soft over entire crease damping.
range, bottoming 11Oil level (oil amount) Increase oil level by about 5~10 mm (0.2~0.4
outin).
Spring Replace with stiff spring.
Stiff toward stroke
1Oil level (oil amount) Decrease oil level by about 5 mm (0.2 in).
end
Soft toward stroke
1Oil level (oil amount) Increase oil level by about 5 mm (0.2 in).
end, bottoming out
Stiff initial
1111Compression dampingTurn adjuster counterclockwise (about 2 clicks)
movement to decrease damping.
Compression damping Turn adjuster clockwise (about 2 clicks) to in-
crease damping.
Low front, tending Rebound damping Turn adjuster counterclockwise (about 2 clicks)
to lower front 11to decrease damping.
postureBalance with rear end Set sunken length for 95~100 mm (3.7~3.9 in)
when one passenger is astride seat (lower rear
posture).
Oil level (oil amount) Increase oil level by about 5 mm (0.2 in).
Compression damping Turn adjuster counterclockwise (about 2 clicks)
to decrease damping.
“Obtrusive” front, Balance with rear end Set sunken length for 90~95 mm (3.5~3.7 in)
tending to upper 11when one passenger is astride seat (upper rear
front postureposture).
Spring Replace with soft spring.
Oil lever (oil amount) Decrease oil level by about 5~10 mm (0.2~0.4
in).
5NY-9-30-7B 5/23/01 9:22 PM Page 22