Operation Manual

CRANKCASE
5-72
EAS25560
DISASSEMBLING THE CRANKCASE
1. Remove:
• Crankcase bolts
TIP
Loosen each bolt 1/4 of a turn at a time, in
stages and in a crisscross pattern. After all of
the bolts are fully loosened, remove them.
•M6 × 35 mm (1.38 in) bolts “1”
•M6 × 50 mm (1.97 in) bolts “2”
•M8 × 110 mm (4.33 in) bolts “3”
2. Remove:
• Left crankcase
ECA13900
Tap on one side of the crankcase with a
soft-face hammer. Tap only on reinforced
portions of the crankcase, not on the
crankcase mating surfaces. Work slowly
and carefully and make sure the crankcase
halves separate evenly.
EAS25580
CHECKING THE CRANKCASE
1. Thoroughly wash the crankcase halves in a
mild solvent.
2. Thoroughly clean all the gasket surfaces
and crankcase mating surfaces.
3. Check:
•Crankcase
Cracks/damage → Replace.
• Oil delivery passages
Obstruction → Blow out with compressed
air.
EAS4B51032
CHECKING THE TIMING CHAIN
1. Check:
• Timing chain
Damage/stiffness → Replace the timing
chain, camshafts and crankshaft assem-
bly as a set.
EAS25700
ASSEMBLING THE CRANKCASE
1. Install:
• Cylinder stud bolts “1”
TIP
For the cylinder stud bolt, embedded height “a”
is the standard value and the tightening torque
is the reference value.
2. Thoroughly clean all the gasket mating sur-
faces and crankcase mating surfaces.
3. Apply:
• Sealant
(onto the crankcase mating surfaces)
TIP
Do not allow any sealant to come into contact
with the oil gallery.
4. Install:
• Dowel pins
• Left crankcase
Cylinder stud bolt
13 Nm (1.3 m·kgf, 9.4 ft·lbf)
a. 150.2–152.2 mm (5.91–5.99 in)
Yamaha bond No.1215
90890-85505
(Three bond No.1215®)