Yamaha 1998 FZS600 5DM1-AE1, Service Manual

Page: 127 / 364

4-15
CYLINDER HEAD
ENG
NOTE:
NOTE:
NOTE:
EB402101
REMOVING THE CYLINDER HEADS
1. Remove:
cylinder head nuts
Loosen the nuts in the proper sequence as
shown.
Loosen each nut 1 / 2 of a turn at a time.
After all of the nuts are fully loosened, re-
move them.
EB402403
CHECKING THE CYLINDER HEADS
The following procedure applies to all of the cyl-
inder heads.
1. Eliminate:
carbon deposits
(from the combustion chambers with a
pounded scraper)
Do not use a sharp instument to avoid dam-
aging or scratching:
spark plug 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 cylin-
der head.
Cylinder head warpage
Less than 0.05 mm
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
cylinder head as follows.
d. Place a 400 600 grit wet sandpaper on
the surface plate and resurface the cylin-
der head using a figure-eight sanding pat-
tern.
To ensure an even surface, rotate the cylin-
der head several times.