Yanmar 6BY2 - Page 90

ENGINE
Cylinder Head
5-28 BY Service Manual
© 2009 Yanmar Marine International
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
Figure 5-39
Figure 5-39
Cylinder Head Torque Specification
7. Install the timing case cover screws
(Figure 5-40, (1)) and tighten.
Figure 5-40
Figure 5-40
Item Specification
First Tighten all bolts to 80 N·m (59 ft-lb)
Second Loosen all bolts at least 180°
Third Tighten all bolts to 50 N·m (37 ft-lb)
Fourth Tighten all bolts an additional 90°
Fifth Tighten all bolts an additional 90°