Rocker Shaft Assembly (Multicylinder) - Yanmar 1GM10 Shop Manual

MULTICYLINDER ENGINES
CYLINDER HEAD
TIGHTENING SEQUENCE
Flywheel
Flywheel
12. Install the rocker assembly and the rocker arm stand
retaining nuts (Figure 10). Tighten the nuts to 37 N*m (27
13. Install the fuel injector and precombustion chamber
as described in Chapter Seven.
14. Install the exhaust manifold.
15. Install the air cleaner base and the air cleaner.
16. Connect the wire lead to the water temperature sender
(Figure 9).
17A. Engines with standard cooling-Connect the lower
water hose (Figure 9).
17B. Engines with freshwater (closed) cooling sys-
tem-Install the freshwater pump as described in Chapter
Eight.
18. Install the alternator.
19. If the engine is installed in the boat, proceed as fol-
lows:
a. Attach the exhaust hose to the exhaust elbow.
b. On engines equipped with a closed cooling system,
fill the cooling system as described in Chapter Four.
c. Connect the negative battery cable to the negative
battery terminal.
Gear 20. Adjust the valve clearance as described in Chapter
Three.
2 1. Reinstall the valve cover.
ROCKER SHAFT ASSEMBLY
Each valve is actuated by a rocker arm that rides on a
shaft (Figure 8). Each rocker arm is equipped with a
bushing in the rocker arm bore. A snap ring at each end of
the rocker arm shaft retains the rocker arms on the rocker
shafts.
1. Remove the valve cover as previously described.
2. Remove the rocker arm stand retaining nuts (Figure
The rocker arms on 2GM and 2GM20 en-
gines are identical, but rocker arms on
are designed for use with the intake or ex-
haust valves.
3. Remove the snap rings at both ends of the rocker shaft
and remove the rocker shaft components.
4. If necessary, unscrew the locating screw in the end
support stand (Figure 15) and separate the rocker shaft
from the stand.
5. Inspect each rocker arm. The pad on the rocker arm
that contacts the valve stem must be smooth. Replace the
rocker arm if the pad is damaged or excessively worn.
Check the adjusting screw push rod seat for galling. Re-
place the adjusting screw if it is damaged or excessively
worn.
109
Screw
NOTE