Removing The Cylinder Head; Checking The Cylinder Head - Yamaha 2002 TDM900 Service Manual

CYLINDER HEAD
EAS00223

REMOVING THE CYLINDER HEAD

1. Remove:
S cylinder head bolts
S cylinder head nuts
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.
EAS00229

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.
S cylinder head water jacket
Mineral deposits/rust ! Eliminate.
3. Measure:
S cylinder head warpage
Out of specification ! Resurface the cylin-
der head.
Maximum cylinder head warpage
Less than 0.10 mm
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.
5-20
ENG