Removing The Cylinder Heads; Checking The Cylinder Heads; Checking The Oil Pipe - Yamaha XV19SX(C) Service Manual

EAS24140

REMOVING THE CYLINDER HEADS

1. Remove:
• Cylinder head nuts
NOTE:
• 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, remove them.
A
2
4
B
A. Front cylinder
B. Rear cylinder
EAS24170

CHECKING THE CYLINDER HEADS

The following procedure applies to all of the cyl-
inder heads.
1. Eliminate:
• Combustion chamber carbon deposits
(with a rounded scraper)
NOTE:
Do not use a sharp instrument to avoid damag-
ing or scratching:
• Spark plug bore threads
• Valve seats
2. Check:
3
3. Measure:
1
M
a. Place a straightedge and a thickness gauge
b. Measure the warpage.
c. If the limit is exceeded, resurface the cylinder
d. Place a 400–600 grit wet sandpaper on the
NOTE:
To ensure an even surface, rotate the cylinder
head several times.
L
EAS24220

CHECKING THE OIL PIPE

1. Check:
5-38
CYLINDER HEADS
• Cylinder head
Damage/scratches → Replace.
• Cylinder head warpage
Out of specification → Resurface the cylinder
head.
Warpage limit
0.03 mm (0.0012 in)
MMM M MMM M M MMM M M MMM M
across the cylinder head.
head as follows.
surface plate and resurface the cylinder head
using a figure-eight sanding pattern.
LLL L LLL L L LLL L L LLL L
• Oil pipe 1
Damage → Replace.
Obstruction → Wash and blow out with com-
pressed air.
M MMM M M MMM M MMM
L LLL L L LLL L LLL