TIP
After replacing the valve guide, reface the valve
seat.
Intake
Valve guide remover (ø5)
90890-04097
Valve guide remover (5.0 mm)
YM-04097
Valve guide installer (ø5)
90890-04098
Valve guide installer (5.0 mm)
YM-04098
Valve guide reamer (ø5)
90890-04099
Valve guide reamer (5.0 mm)
YM-04099
Exhaust
Valve guide remover (ø4.5)
90890-04116
Valve guide remover (4.5 mm)
YM-04116
Valve guide installer (ø4.5)
90890-04117
Valve guide installer (4.5 mm)
YM-04117
Valve guide reamer (ø4.5)
90890-04118
Valve guide reamer (4.5 mm)
YM-04118
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3. Eliminate:
• Carbon deposits
(from the valve face and valve seat)
4. Check:
• Valve face
Pitting/wear Grind the valve face.
• Valve stem end
Mushroom shape or diameter larger than
the body of the valve stem Replace the
valve.
5. Measure:
• Valve margin thickness "a"
Out of specification Replace the valve.
VALVES AND VALVE SPRINGS
Valve margin thickness (intake)
1.20 mm (0.0472 in)
Valve margin thickness (exhaust)
0.85 mm (0.0335 in)
6. Measure:
• Valve stem runout
Out of specification Replace the valve.
TIP
• When installing a new valve, always replace
the valve guide.
• If the valve is removed or replaced, always re-
place the valve stem seal.
Valve stem runout
0.010 mm (0.0004 in)
CHECKING THE VALVE SEATS
EAS2GBB252
1. Eliminate:
• Carbon deposits
(from the valve face and valve seat)
2. Check:
• Valve seat
Pitting/wear Replace the cylinder head.
3. Measure:
• Valve seat contact width "a"
Out of specification Replace the cylinder
head.
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