Removing The Cylinder Head; Checking The Cylinder Head - Yamaha YZF-R15 Service Manual

REMOVING THE CYLINDER HEAD

1. Align:
• "I" mark "a" on the magneto rotor
(with the stationary pointer "b" on the magneto
cover)
s s s s s s s s s s s s s s s s s s s s s s s s s s
a. Turn the crankshaft counterclockwise.
b. When the piston is at TDC on the compres-
sion stroke, align the "I" mark "c" on the cam-
shaft sprocket with the mark "d" on the
cylinder head.
d
c
ssssssssssssssssssssssssss
2. Loosen:
• Camshaft sprocket bolt "1"
NOTE:
While holding the magneto rotor nut with a
wrench "2", loosen the camshaft sprocket bolt.
1
2
3. Remove:
• Camshaft sprocket
NOTE:
To prevent the timing chain from falling into the
crankcase, fasten it with a wire "1".
1
b
4. Remove:
• Cylinder head
NOTE:
• Loosen the bolts in the proper sequence as
shown.
a
• Loosen each bolt 1/2 of a turn at a time. After
all of the bolts are fully loosened, remove them.

CHECKING THE CYLINDER HEAD

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
5-8
CYLINDER HEAD
4
6
2
1
3
5