Yanmar BY Series Service Manual page 90

ENGINE
6. Lightly oil threads of new bolts and install new
bolts. Tighten the bolts in stages, and in the
sequence shown (Figure 5-37) and
(Figure 5-38). Use a torsion angle tool such as
that shown (Figure 5-39). NOTICE: NEVER
reuse cylinder head bolts. New bolts must be
installed whenever they are removed. NEVER
wash off bolt coating.
Figure 5-374BY2 Engine
Figure 5-37
Figure 5-386BY2 Engine
Figure 5-38
5-28
Figure 5-39
Cylinder Head Torque Specification
Item
First
Second
Third
Fourth
Fifth
7. Install the timing case cover screws
(Figure 5-40, (1)) and tighten.
Figure 5-40
© 2009 Yanmar Marine International
Cylinder Head
Figure 5-39
Specification
Tighten all bolts to 80 N·m (59 ft-lb)
Loosen all bolts at least 180°
Tighten all bolts to 50 N·m (37 ft-lb)
Tighten all bolts an additional 90°
Tighten all bolts an additional 90°
Figure 5-40
BY Service Manual