Yamaha YZF-R25 Service Manual page 242

• Align the projection "c" on the engine mounting
bolt cap with the portion "d" of the front cowling
assembly stay.
2
d
2. Install:
• Cylinder head
• Cylinder head bolt (M10) (×6)
• Cylinder head bolt (M6) (×2)
TIP
• Pass the timing chain through the timing chain
cavity.
• Lubricate the cylinder head bolt (M10) threads
and mating surface with molybdenum disulfide
grease.
3. Tighten:
• Cylinder head bolts "1"–"6"
• Cylinder head bolts "7", "8"
Cylinder head bolt ("1"–"6")
1st: 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
2nd: 30 Nm (3.0 m·kgf, 22 ft·lbf)
*3rd: 12 Nm (1.2 m·kgf, 8.7 ft·lbf)
Specified angle 115–125°
Cylinder head bolt ("7", "8")
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
* Following the tightening order, loosen the
bolt one by one, and then retighten it to the
specific torque.
ECA20890
NOTICE
Do not use a torque wrench to tighten the
bolt to the specified angle.
b
a
1
c
5-25
CYLINDER HEAD
TIP
Tighten the cylinder head bolts in the tightening
sequence as shown and torque them in 3 stag-
es.
×2
×6
1
3
5
2
4. Install:
• Timing chain bolt (right side of cylinder head)
"1"
Timing chain bolt (right side of
cylinder head)
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
TIP
Make sure that the timing chain bolt passes
through the timing chain "2".
1
FWD
2