Yamaha MBK X-MAX 300 2017, Service Manual

Page: 212 / 462

CYLINDER HEAD
5-17
EAS30276
REMOVING THE CYLINDER HEAD
1. Remove:
• Crankshaft end cover
• Timing mark accessing bolt
2. Align:
• Mark “a” on the generator rotor
(with the slots “b” in the generator rotor cover)
a. Turn the crankshaft clockwise.
b. Position the mark “a” on the generator ro-
tor on both sides of the slots “b” in the gen-
erator rotor cover.
TIP
When the piston is at TDC on the compression
stroke, align the “I” mark “c” on the camshaft
sprocket with the match mark “d” on the cylinder
head.
3. Remove:
• Camshaft sprocket bolts “1”
• Camshaft sprocket
TIP
• Use the camshaft sprocket stopper “2” and
loosen the camshaft sprocket bolts.
• To prevent the timing chain from falling into the
crankcase, fasten it with a wire.
4. Remove:
• 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.
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
2. Check:
• Cylinder head
Damage/scratches
→
Replace.
Camshaft sprocket stopper
90890-04182
Camshaft sprocket stopper
YM-04182
b
a
d
c
1
2
3 6
2 1
5
4
×4
×2