Yanmar BY Series Service Manual page 88

Cylinder Head
IMPORTANT
NEVER reuse cylinder head bolts. New
bolts must be installed whenever they are
removed. DO NOT wash off bolt coating.
6. Lightly oil threads of new bolts and install new
bolts. Tighten the bolts in stages, and in the
sequence shown (Figure 5-37). Use a torsion
angle tool such as that shown (Figure 5-38).
Cylinder Head Torque Specification
Item
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°
Figure 5-39
7. Install the timing case cover screws
(Figure 5-39, (1)) and tighten.
BY Service Manual
Specification
Figure 5-40
8. Install high-pressure pump-to-fuel rail line
(Figure 5-40, (1)).
4BY Engines: Install rubber mount
(Figure 5-40, (3)).
9. Install glow plugs (Figure 5-40, (2)).
10. Install high-pressure fuel rail. See Removing
and Installing Fuel Rail on page 6-27.
( 1 )
Figure 5-41
11. Connect harness connector to temperature
sensor (Figure 5-41, (2)).
12. Install coolant branch fitting with a new seal and
tighten bolts (Figure 5-41, (1)).
ENGINE
( 2 )
0003767
5-33