Removing The Cylinder Head; Checking The Cylinder Head - Yamaha WR125R 2009 Service Manual

EAS24130

REMOVING THE CYLINDER HEAD

1. Align:
• "I" mark "a" on the generator rotor
(with the stationary pointer "b" on the genera-
tor cover)
M MMM M MMM M M MMM M
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 stationary pointer "d"
on the cylinder head.
d
c
L LLL L LLL L L LLL L
2. Loosen:
• Camshaft sprocket bolt "1"
TIP
While holding the generator rotor nut with a
wrench "2", loosen the camshaft sprocket bolt.
1 1 1
3. Remove:
• Camshaft sprocket
M MMM M M MMM M M MMM M
a
L LLL L L LLL L L LLL L
2
TIP
To prevent the timing chain from falling into the
crankcase, fasten it with a wire "1".
MMM
1
b
4. Remove:
• Cylinder head
TIP
• Loosen the bolts in the proper sequence as
shown.
• Loosen each bolt 1/2 of a turn at a time. After
all of the bolts are fully loosened, remove them.
• Remove the cylinder head from the right side
of the vehicle.
LLL
EAS24160

CHECKING THE CYLINDER HEAD

1. Eliminate:
• Combustion chamber carbon deposits
(with a rounded scraper)
TIP
Do not use a sharp instrument to avoid damag-
ing or scratching:
• Spark plug bore threads
• Valve seats
5-9
CYLINDER HEAD
4
6
2
1
3
5