Removing The Cylinder Head; Checking The Cylinder Head - Yamaha MBK MW125 2014 Service Manual

EAS30276

REMOVING THE CYLINDER HEAD

1. Align:
• "I" mark "a" on the AC magneto rotor
(with the match mark "b" on the right crank-
case)
▼ ▼▼▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼
a. Turn the crankshaft clockwise.
b. When the piston is at TDC on the compres-
sion stroke, align the "I" mark "c" on the cam-
shaft sprocket with the match mark "d" on the
camshaft stopper plate.
c
▲ ▲▲▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲
2. Loosen:
• Camshaft sprocket bolt "1"
TIP
While holding the AC magneto rotor nut with a
wrench "2", loosen the camshaft sprocket bolt.
1
3. Remove:
• Timing chain tensioner
(along with the gasket)
• Camshaft sprocket bolt "1"
• Camshaft sprocket "2"
▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼
d
▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲
2
TIP
To prevent the timing chain from falling into the
crankcase, fasten it with a wire.
▼▼▼
b
a
4. Remove:
• Camshaft stopper plate
• Cylinder head
TIP
• Loosen the bolts and nuts in the proper se-
quence as shown.
• Loosen each bolt and nuts 1/2 of a turn at a
time. After all of the bolts and nuts are fully
loosened, remove them.
6
3
▲▲▲
EAS30277

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
5-12
CYLINDER HEAD
1
2
2
4
1
5
×
4
×
2