Removing The Cylinder Head; Checking The Cylinder Head - Yamaha YZF-R1S Service Manual

CYLINDER HEAD
EAS00222

REMOVING THE CYLINDER HEAD

1. Remove:
S intake camshaft
S exhaust camshaft
Refer to "REMOVING THE CAMSHAFTS".
2. Remove:
S cylinder head nuts
S cylinder head bolts
NOTE:
S Loosen the nuts in the proper sequence as
shown.
S Loosen each nut 1/2 of a turn at a time. After all
of the nuts are fully loosened, remove them.
EAS00227

CHECKING THE CYLINDER HEAD

1. Eliminate:
S combustion chamber carbon deposits
(with a rounded scraper)
NOTE:
Do not use a sharp instrument to avoid damag-
ing or scratching:
S spark plug bore threads
S valve seats
2. Check:
S cylinder head
Damage/scratches ! Replace.
3. Measure:
S cylinder head warpage
Out of specification ! Resurface the cylin-
der head.
Maximum cylinder head warpage
0.10 mm (0.0039 in)
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 cylinder
head as follows.
d. Place a 400 X 600 grit wet sandpaper on the
surface plate and resurface the cylinder
head using a figure-eight sanding pattern.
NOTE:
To ensure an even surface, rotate the cylinder
head several times.
5-23
ENG