2003 YAMAHA WR 450F Notices Demploi (in French)

Page 369 of 754

YAMAHA WR 450F 2003  Notices Demploi (in French) ENG
4 - 34
SOUPAPES ET RESSORTS DE SOUPAPE
VENTILE UND VENTILFEDERN
VÁLVULAS Y MUELLES DE VÁLVULA
AUSBAU
1. Demontieren: 
Tassenstößel 1 
Ventilplättchen 2 
HINWEIS:
Die jeweilige Einbaulage de

Page 370 of 754

YAMAHA WR 450F 2003  Notices Demploi (in French) 4 - 35
ENGVALVES AND VALVE SPRINGS
INSPECTION
Valve
1. Measure:
Stem-to-guide clearance
Out of specification → Replace the
valve guide. Stem-to-guide clearance =
valve guide inside diameter a –

Page 371 of 754

YAMAHA WR 450F 2003  Notices Demploi (in French) ENG
4 - 35
SOUPAPES ET RESSORTS DE SOUPAPE
VENTILE UND VENTILFEDERN
VÁLVULAS Y MUELLES DE VÁLVULA
PRÜFUNG
Ventil
1. Messen:
Ventilschaftspiel
Unvorschriftsmäßig → Ven-
tilführung erneuern. Ve

Page 372 of 754

YAMAHA WR 450F 2003  Notices Demploi (in French) 4 - 36
ENGVALVES AND VALVE SPRINGS
Valve guide remover:
Intake: 4.5 mm (0.18 in)
YM-4116/90890-04116
Exhaust: 5.0 mm (0.20 in)
YM-4097/90890-04097
Valve guide installer:
Intake:
YM-4117/90890-04117
Ex

Page 373 of 754

YAMAHA WR 450F 2003  Notices Demploi (in French) ENG
4 - 36
SOUPAPES ET RESSORTS DE SOUPAPE
VENTILE UND VENTILFEDERN
VÁLVULAS Y MUELLES DE VÁLVULA
Ventilführungs-Austreiber
Einlaß (4,5 mm)
YM-4116/
90890-04116
Auslaß (5,0 mm)
YM-4097/
90890-040

Page 374 of 754

YAMAHA WR 450F 2003  Notices Demploi (in French) 4 - 37
ENGVALVES AND VALVE SPRINGS
5. Measure:
Runout (valve stem)
Out of specification → Replace.
NOTE:
When installing a new valve always replace
the guide.
If the valve is removed or replaced

Page 375 of 754

YAMAHA WR 450F 2003  Notices Demploi (in French) ENG
4 - 37
SOUPAPES ET RESSORTS DE SOUPAPE
VENTILE UND VENTILFEDERN
VÁLVULAS Y MUELLES DE VÁLVULA
5. Messen:
Ventilschaftschlag
Unvorschriftsmäßig → 
Erneuern.
HINWEIS:
Beim Einbau eines neuen

Page 376 of 754

YAMAHA WR 450F 2003  Notices Demploi (in French) 4 - 38
ENGVALVES AND VALVE SPRINGS
9. Lap:
Valve face
Valve seat
NOTE:
After refacing the valve seat or replacing the
valve and valve guide, the valve seat and
valve face should be lapped.
Lapping s