Yamaha YZF-R1S Service Manual - Eng
5-29
VALVES AND VALVE SPRINGS
ENG
NOTE:
NOTE:
After replacing the valve guide, reface the valve
seat.
Valve guide remover
Intake (4.0 mm, 0.16 in)
90890-04111
Exhaust (4.5 mm, 0.18 in)
90890-04116, YM-4116
Valve guide installer
Intake (4.0 mm, 0.16 in)
90890-04112
Exhaust (4.5 mm, 0.18 in)
90890-04117, YM-4117
Valve guide reamer
Intake (4.0 mm, 0.16 in)
90890-04113
Exhaust (4.5 mm, 0.18 in)
90890-04118, YM-4118
3. Eliminate:
Scarbon deposits
(from the valve face and valve seat)
4. Check:
Svalve face
Pitting/ wear
! Grind the valve face.
Svalve stem end
Mushroom shape or diameter larger than the
body of the valve stem
! Replace the valve.
5. Measure:
Svalve margin thickness
a
Out of specification
! Replace the valve.
Valve margin thickness
0.5
X 0.9 mm
(0.0197
X 0.0354 in)
6. Measure:
Svalve stem runout
Out of specification
! Replace the valve.
SWhen installing a new valve, always replace
the valve guide.
SIf the valve is removed or replaced, always re-
place the oil seal.
Valve stem runout
0.01 mm (0.0004 in)