4-22
VALVES AND VALVE SPRINGS
REMOVING THE VALVE LIFTER
AND VALVE COTTER
1. Remove:
• Valve lifter "1"
• Pad "2"
Identify each lifter "1" and pad "2" po-
sition very carefully so that they can
be reinstalled in their original place.
2. Check:
• Valve sealing
Leakage at the valve seat
→
In-
spect the valve face, valve seat
and valve seat width.
Checking steps:
a. Pour a clean solvent "1" into the
intake and exhaust ports.
b. Check that the valve seals prop-
erly.
There should be no leakage at the
valve seat "2".
3. Remove:
• Valve cotter
Attach a valve spring compressor "1"
between the valve spring retainer and
the cylinder head to remove the valve
cotters.
CHECKING THE VALVE
1. Measure:
• Stem-to-guide clearance
Out of specification
→
Replace
the valve guide.
2. Replace:
• Valve guide
Replacement steps:
To ease guide removal, installation
and to maintain correct fit heat the
cylinder head in an over to 100 °C
(212 °F).
a. Remove the valve guide using a
valve guide remover "1".
b. Install the new valve guide using a
valve guide remover "1" and valve
guide installer "2".
c. After installing the valve guide,
bore the valve guide using a valve
guide reamer "3" to obtain proper
stem-to-guide clearance.
After replacing the valve guide reface
the valve seat.
3. Inspect:
• Valve face
Pitting/wear
→
Grind the face.
• Valve stem end
Mushroom shape or diameter
larger than the body of the stem
→
Replace.
Valve spring compres-
sor:
YM-4019/90890-04019
Stem-to-guide clearance = valve
guide inside diameter "a" -
valve stem diameter "b"
Clearance (stem to
guide):
Intake:
0.010–0.037 mm
(0.0004–0.0015 in)
<Limit>:0.08 mm
(0.003 in)
Exhaust:
0.025–0.052 mm
(0.0010–0.0020 in)
<Limit>:0.10 mm
(0.004 in)
Valve guide remover:
Intake:4.0 mm (0.16 in)
YM-4111/90890-04111
Exhaust:4.5 mm (0.18
in)
YM-4116/90890-04116
Valve guide installer:
Intake:4.0 mm (0.16 in)
YM-4112/90890-04112
Exhaust:4.5 mm (0.18
in)
YM-4117/90890-04117
Valve guide reamer:
Intake:4.0 mm (0.16 in)
YM-4113/90890-04113
Exhaust:4.5 mm (0.18
in)
YM-4118/90890-04118
Содержание YZ250F(X)
Страница 2: ......
Страница 37: ...2 17 LUBRICATION DIAGRAMS 1 Crankshaft 2 Oil filter element 3 Oil tank 4 Oil hose A From oil pump ...
Страница 57: ...3 13 ENGINE INTAKE EXHAUST ...
Страница 108: ...4 41 OIL PUMP 15 Rotor housing 1 Order Part name Q ty Remarks ...
Страница 159: ...5 29 STEERING 9 Bearing race 2 Refer to removal section Order Part name Q ty Remarks ...
Страница 168: ...5 38 REAR SHOCK ABSORBER 12 Bearing 2 Refer to removal section Order Part name Q ty Remarks ...
Страница 243: ...3 13 MOTEUR ADMISSION ECHAPPEMENT ...
Страница 275: ...4 21 CULASSE 7 Carter de chaîne de distribution côté échappe ment 1 Ordre Nom de la pièce Qté Remarques ...
Страница 298: ...4 44 BALANCIER 5 Replier l onglet de la rondelle frein ...
Страница 300: ...4 46 POMPE A HUILE 14 Arbre d entraînement de pompe à huile 1 15 Boîtier du rotor 1 Ordre Nom de la pièce Qté Remarques ...
Страница 361: ...5 38 AMORTISSEUR ARRIERE 12 Roulement 2 Se reporter à la section de dépose Ordre Nom de la pièce Qté Remarques ...
Страница 384: ......
Страница 419: ...2 17 SCHMIERSYSTEM SCHAUBILDER 1 Kurbelwelle 2 Ölfiltereinsatz 3 Öltank 4 Ölschlauch A Von der Ölpumpe ...
Страница 439: ...3 13 MOTOR EINLASS AUSLASS ...
Страница 495: ...4 45 ÖLPUMPE 15 Rotorgehäuse 1 Reihenfolge Bauteil Anz Bemerkungen ...
Страница 555: ...5 38 FEDERBEIN 12 Lager 2 Siehe den Abschnitt zum Ausbau Reihenfolge Bauteil Anz Bemerkungen ...
Страница 578: ......
Страница 634: ...3 14 MOTORE ASPIRAZIONE SCARICO ...
Страница 685: ...4 40 ELEMENTO FILTRO OLIO E POMPA DELL ACQUA Applicare il grasso a base di sapone di litio sulla guarnizione circolare ...
Страница 688: ...4 43 EQUILIBRATORE 5 Piegare la linguetta della rondella di bloccaggio ...
Страница 690: ...4 45 POMPA DELL OLIO 15 Alloggiamento del rotore 1 Ordine Denominazione Quantità Osservazioni ...
Страница 774: ......
Страница 775: ......