Checking The Cylinder Head - Yamaha F30B 2018 Service Manual

5. Remove:
• Valve cotter
• Retainer
• Valve spring
• Valve spring seat
• Intake valve
• Exhaust valve
TIP:
Make sure to keep the parts in the order of re-
moval.
2
1
Valve spring compressor "1"
90890-04019
Valve spring compressor "1"
YM-04019
Valve spring compressor attach-
ment "2"
90890-06320
Valve spring compressor adaptor
"2"
YB-06320

Checking the cylinder head

1. Check:
• Cylinder head
Damage/scratches  Replace.
• Cylinder head warpage
Out of specification  Replace.
Warpage limit
0.10 mm (0.0039 in)
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a. Remove carbon deposits from the com-
bustion chambers, and then check the cyl-
inder head for damage and scratches.
b. Check the cylinder head warpage using a
straightedge "1" and a thickness gauge "2"
in 7 directions.
1
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7-32
Camshaft and valve
2