Removing The Cylinder Head; Checking The Cylinder Head - Yamaha YZF-R1 1998 Service Manual

CYLINDER HEAD
EB402102

REMOVING THE CYLINDER HEAD

1. Remove:
• cylinder head bolts
• cylinder head nuts
NOTE:
Loosen each bolt and nut 1/2 of a turn at
a time, in stages and in a crisscross pat-
tern. After all of the bolts and nuts are
fully loosened, remove them.
EB402402

CHECKING THE 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.
• cylinder head water jacket
Mineral deposits/rust → Eliminate.
3. Measure:
• cylinder head warpage
Out of specification → Resurface the
cylinder head.
Max. cylinder head warpage
0.1 mm
a. Place a straightedge 1 and a thick-
ness gauge 2 across the cylinder
head.
b. Measure the warpage.
c. If the limited is exceeded, resurface
the cylinder head as follows.
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ENG