Yamaha YZF-R25 Service Manual page 230

EAS30256
REMOVING THE CAMSHAFTS
1. Remove:
• Crankshaft end cover "1"
• Timing mark accessing bolt "2"
1
2. Align:
• Marks "a" on the generator rotor
(with the slots "b" in the generator rotor cover)
• Punch mark "c" on the balancer drive gear
(with the projections "d" on the timing chain
guide (lower side))
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a. Turn the crankshaft counterclockwise.
b. Position the marks "a" on the generator rotor
on both sides of the slots "b" in the generator
rotor cover.
c. Position the punch mark "c" on the balancer
drive gear "1" between the projections "d" on
the timing chain guide (lower side) "2".
c
1
2
▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼
b
a
d
2
TIP
When the alignment mark "e" on the intake cam-
shaft sprocket and the alignment mark "f" on the
exhaust camshaft sprocket are aligned with the
edge "g" of the cylinder head, piston #1 is at 90°
ATDC.
e
g
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3. Remove:
• Timing chain tensioner "1"
• Timing chain tensioner gasket
▼▼▼
▼ ▼▼▼ ▼ ▼▼▼ ▼
a. Insert the hexagon wrench "2" (part No.:
1WS-12228-00) into the timing chain tension-
er.
b. Remove the timing chain tensioner.
▲ ▲▲▲ ▲ ▲▲▲ ▲
4. Remove:
• Intake camshaft cap "1"
• Exhaust camshaft cap "2"
ECA13720
NOTICE
To prevent damage to the cylinder head,
camshafts or camshaft caps, loosen the
camshaft cap bolts in stages and in a criss-
cross pattern, working from the outside in.
5-13
CAMSHAFTS
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▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼ ▼ ▼▼▼ ▼
2
1
▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲ ▲ ▲▲▲ ▲
f
g
▲ ▲▲▲ ▲ ▲▲▲
▼ ▼▼▼ ▼ ▼▼▼
▲ ▲▲▲ ▲ ▲▲▲