Removing The Cylinder Heads; Checking The Cylinder Heads - Yamaha XV16AL Service Manual

5
CYLINDER HEADS

REMOVING THE CYLINDER HEADS

1. Remove:
• cylinder head
NOTE:
• Loosen the nuts in the proper sequence.
• Follow the numerical order shown in the
illustration. Loosen each bolt 1/4 of a turn
at a time until all of the nuts are loose.
EAS00228

CHECKING THE CYLINDER HEADS

The following procedure applies to each
cylinder head.
1. Eliminate:
• combustion chamber carbon deposits
(with a rounded scraper)
NOTE:
Do not use a sharp instrument to avoid
damaging or scratching:
• spark plug bore threads
• valve seats
2. Check:
• cylinder head
Damage/scratches → Replace.
3. Measure:
• cylinder head warpage
Out of specification → Resurface the cyl-
inder head.
Maximum cylinder head warpage
0.10 mm (0.0039 in)
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a. Place a straightedge 1 and a thickness
gauge 2 across the cylinder head.
b. Measure the warpage.
c. If the limit is exceeded, resurface the cyl-
inder head as follows.
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