Doosan DX60R Shop Manual page 305

5. To assure the valve bridge contacts the rear valve, apply
light, downward (4, Figure 162) finger pressure on the
valve bridge (3, Figure 162), and loosen the valve bridge
adjusting screw (1, Figure 162), until there is visible
clearance (2, Figure 164) between the adjusting screw
and the front valve.
6. To assure the valve bridge has equal contact with the front
and rear valves, apply light downward (4, Figure 162)
pressure on the valve bridge (3, Figure 162), adjust the
valve bridge adjusting screw ((1, Figure 162), (1, Figure
164)) so there is zero "0" clearance (2, Figure 164)
between the adjusting screw and the front valve.
7. Tighten the lock nut (1, Figure 163), while holding the
valve bridge (3, Figure 163) with a wrench (2, Figure 163).
Verify that the valve clearance (2, Figure 164) is zero "0".
NOTE:
Note: There is a tendency for the clearance to
decrease slightly when the lock nut is tightened.
It is suggested that you make the initial
clearance adjustment is made slightly on the
"loose" side before tightening the lock nut.
Engine
Figure 162
Figure 163
Figure 164
SP001693
Page 125