Yamaha FZS1000N, Service Manual

Page: 220 / 394

5-17
CYLINDER HEAD
ENG
NOTE:
NOTE:
NOTE:
EAS00223
REMOVING THE CYLINDER HEADS
1. Remove:
R
cylinder head nuts
R
cylinder head cap nuts
R
cylinder head bolts
R
Loosen the nuts in the proper sequence as
shown.
R
Loosen each nut 1 / 2 of a turn at a time. After all
of the nuts are fully loosened, remove them.
EAS00230
CHECKING THE CYLINDER HEADS
The following procedure applies to all of the cyl-
inder heads.
1. Eliminate:
R
carbon deposits
(from the combustion chambers with a
rounded scraper)
Do not use a sharp instrument to avoid damag-
ing or scratching:
R
spark plug threads
R
valve seats
2. Check:
R
cylinder head
Damage / scratches
!
Replace.
R
cylinder head water jacket
Mineral deposits / rust
!
Eliminate.
3. Measure:
R
cylinder head warpage
Out of specification
!
Resurface the cylin-
der head.
Cylinder head warpage
Less than 0.1 mm (0.004 in)
a. Place a straightedge 1 and a thickness
gauge 2 across the cylinder head.
b. Measure the warpage.
c. If the limited is exceeded, resurface the cylin-
der 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.
To ensure an even surface, rotate the cylinder
head several times.