Checking The Valve Seats - Yamaha 2008 Fazer FZ1-N Service Manual

Intake
Valve guide remover (ø4)
90890-04111
YM-04111
Exhaust
Valve guide remover (ø4.5)
90890-04116
YM-04116
Intake
Valve guide installer (ø4)
90890-04112
YM-04112
Exhaust
Valve guide installer (ø4.5)
90890-04117
YM-04117
Intake
Valve guide reamer (ø4)
90890-04113
YM-04113
Exhaust
Valve guide reamer (ø4.5)
90890-04118
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.
Valve margin thickness
0.5–0.9 mm (0.0197–0.0354 in)
Limit
0.5 mm (0.02 in)
VALVES AND VALVE SPRINGS
6. Measure:
• Valve stem runout
Out of specification → Replace the valve.
NOTE:
• When installing a new valve, always replace
the valve guide.
• If the valve is removed or replaced, always
replace the oil seal.
Valve stem runout
0.010 mm (0.0004 in)
EAS24300

CHECKING THE VALVE SEATS

The following procedure applies to all of the
valves and valve seats.
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 width "a"
Out of specification → Replace the cylin-
der head.
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