Yanmar 1GM User Manual page 102

Pliers
Remove plug
96
CHAPTE R FIVE
Cylinder block
Core plug
Strike here
Wlthh7
Drift
Core plugs in the cylinder block prevent damage to the
block should the coolant freeze .
NOTE
Core plugs can he replaced inexpensively by
a machine shop. If machine work is being
performed on the engine, have the core
plugs replaced at the same time.
Removal/Installation
CAUTION
Do not drive core plugs into the engine cast-
ing.
It will
he impossible to retrieve them
and they can restrict coolant circulation, re-
suIting in serious engine damage.
Sealing edge
beforeinstallation
~l-----:c:o:ce~p:,~"--g~lnstaliation
tool
. .. . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . .n
Cup type plug
1. Tap the bottom edge of the core plug with a hammer
and drift. Usc several sharp blows to push the bottom of
the plug inward, tilting the top out (Figure 90).
2. Grip the top ofthe plug finnlywith pliers . Pull the plug
from its bore (Ftgurc 91) and discard it.
NOTE
The core plugs can also be removed hydrill-
ing a hole in the center ofthe plug and pry-