Yanmar 1GM User Manual page 172

166
Remeva l/l nstal lati on
Seawater cooling system.f
The thermostat on 1GM and IGM I0 engines is located
in the cylinder head ( Flgu re 2). The thermostat on two-
and three-cylinder engines is located in the thermostat
housing (Fi gure 3 and Flg ure 4 ). 311M and 3HM35 en-
gines arc equipped with two thermostats ( Figure 4 ).
1.
Drain the seawater from the engine as desc ribed in
Chapter Four.
2. Loo sen the hose clamps and disconnect the hoses from
the thermostat cover (Figu re 8).
3. Remove the thermostat cover retaining bolts and
washers. Remove the cover and the gasket. Discard the
gasket.
4. Remove the thermosta t (Figure 9). On 3HM and
311 M35 engines, remove be th.
5. Test the thermostats as described in this chapter.
6. Clean the thermostats cover and housing or cy linder
head mating surfaces of all gasket residue.
7. Install the thermostat in the housing or cylinder head
with its thermostatic element facing the engine. The ther-
mostat flange must fit into the housing recess.
8. Coat both sides ofa new gasket with sealant and insta ll
the gasket onto the thermostat cover.
9. Install the cove r. Note tha t the inlet and outlet nipples
arc stepped. Install the cove r so the outermost nipple faces
down, as shown in Ftgurc 10. Tighten the bolts securely.
10. Reconnect the hoses to the thermostat cover and
tighten the clamps securely.
11. Operate the engine and check for leaks. Operate the
engine until it reaches normal operating temperature. Im-
mediately shut down the engine ifoverheating occurs and
correct the problem .
C HAPT ER EIG HT
DOWN
Freshwater cooling systems
I . Drain the coo lant from the engi ne as described in
Chapter Four.
2. Loosen the hose clamp (Ffgu re II ) securing the cool-
anthosclothethermostateove~
3. Remove the thermostat cove r reta ining bolts and
washers( Figu ~ II ). Remove the cove r and the hose. Dis-
car d the gas ket.
4. Remove the thermo stat (F igu re 12).
5. Test the thermostat as described in this chapter.
6. C lean the thermostat cover and housing mating sur-
faces of all gasket residue .
7. Install the thermostat in the housing with its thermo-
static element facing the housing. The thermostat flange
must fit into the housing recess.
8. Coat both sides ofa new gas ket with sea lant and install
the gas ket onto the thermostat cover.