Thermostat; Seawater Pump And Impeller - Kohler 4EOZ Service

6.2 Thermostat

In a direct seawater cooling system, the impeller pump
circulates the seawater around the cylinder and through
the cylinder head. A thermostat controls the cooling water
circuit temperature. See Figure 6-2 for thermostat
settings. Consult the engine operation manual for the
thermostat cleaning and checking procedures.
Thermostat Settings
(Max. Temp.)
Seawater
50_C (122_F)
Freshwater 75_C (167_F)
Figure 6-2 Thermostat Settings

6.3 Seawater Pump and Impeller

The gear driven seawater pump is located on the
alternator side of the generator set. Check and change
the seawater pump impeller at the interval specified in
the service schedule. Follow the instructions included
with the impeller kit. If the instructions are not included
with the kit, use the following procedure:
Impeller Inspection and Replacement Procedure:
1. Close the seacock.
2. Remove the seawater pump coverplate.
Figure 6-3.
1
1. Seawater pump
2. Coverplate
3. Gasket
Figure 6-3 Seawater Pump, Typical
32 Section 6 Cooling System
2
3
4
5
6
TP-6053
4. Impeller
5. Bearing
6. Housing
3. Remove the impeller.
4. Inspect the impeller for damaged, cracked, broken,
missing or flattened vanes. The impeller vanes
should be straight and flexible. See Figure 6-4.
Replace the impeller if it is damaged.
1. Flattened vane
2. Crack
3. Broken vane
Figure 6-4 Worn Impeller
5. Lubricate the impeller with soapy water before
installation.
6. Install the impeller.
Note: During installation push and rotate the
impeller in the same direction as the engine
See
rotation until it is thoroughly seated in the
impeller housing.
7. Inspect the coverplate and gasket for corrosion
and/or damage.
necessary.
8. Lubricate the gasket with silicon grease and attach
the gasket and coverplate to the seawater pump
housing.
9. Open the seacock.
10. Start the generator set and check for leaks.
11. Stop the generator set and repair leaks or replace
damaged or worn components.
1
2
3
TP-6053
Replace components as
m:sm:003:008
TP-6137 5/03