818165 Mariner SCREW, (.375-16 x 1.75)

Checking Oil Pressure Gauge Reading
After starting and during operation, frequently observe the oil pressure gauge. If the gauge indicator registers below "NORMAL", or if the indicator fluctuates, check the oil level and take corrective measures.Checking Oil Level
Check the oil level with the engine idling. Oil level must be between the ADD and FULL marks on the oil level gauge. Add oil as required. See Lubrication and Maintenance Chart for proper oil.
CHECKING CRANKCASE OIL LEVELDraining Crankcase Lube Oil
With engine stopped and oil warm:1. Wipe dirt from the right hand oil filter housing cover.2. Remove the vent plug.3. Open the oil filter housing drain valve.
VENT PLUG AND DRAIN VALVE4. Remove the oil cooler drain plug.
OIL COOLER DRAIN PLUGS5. Remove the oil pan drain plug.
OIL PAN DRAIN PLUGIf a sump pump is used:a. Connect a suitable drain to the pump outlet.
SUMP PUMP VALVES AND PUMP OUTLETb. Open the valve to the engine crankcase.c. Close the valve to the marine gear housing.d. Operate the sump pump handle until the crankcase is empty.e. Close the valve to the engine crankcase.Cleaning Breather(s) (D379, D398, D399 Engines)
1. D399 Engine Only: Loosen the front hose clamp from the breather tube.
LOOSENING HOSE CLAMP2. All Engines: Remove breather mounting bolts. Lift off breathers.
REMOVING BREATHERS3. D399 Engine Only: Remove and inspect the upper and lower hoses from the breathers.4. All Engines: Wash the breather(s) in clean diesel fuel or solvent.5. All Engines: Install breather(s).6. D399 Engine Only: Install lower and upper hose. Tighten all clamps. Connect breather tube.Cleaning Breather(s) (D346, D348, D349 Engines)
One breather is mounted on the left front valve cover. On D349 Engines, a second breather is mounted on the right rear valve cover. Service both breathers when so equipped.1. Loosen the hose clamp.
LOOSENING HOSE CLAMP2. Loosen the cover bolt and lift off the breather cover.
REMOVING THE BREATHER COVER3. Remove and inspect breather element.
REMOVING BREATHER ELEMENT4. Wash breather element in clean diesel fuel or kerosene.5. Install breather element and cover. Connect hose.Oil Filter Service Indicator
Checking Oil Filter Change Indicator
When the engine is operating under full load with the oil at operating temperature, observe the position of the red plunger of the indicator. When the plunger rises approximately half the height of the plastic window, install new oil filter elements.
OIL FILTER SERVICE INDICATOR (Filter housing)
OIL FILTER SERVICE INDICATOR (Left cover)If the normal oil filter period occurs before the plunger rises, change the oil filter elements at that time. See the LUBRICATION CHART for the oil filter change period.Oil Filter Elements
Installing Oil Filter Elements
If your engine is equipped with a standard oil filter system, read the following instructions. If your engine is equipped to permit changing the oil filter elements while the engine is running, read the topic, "DUPLEX OIL FILTER SYSTEM".Installing Oil Filter Elements
1. Drain the oil filter housing.
VENT PLUG AND DRAIN VALVE2. Remove the right hand cover from the filter housing.
OIL FILTER HOUSING COVER3. Remove the oil filter elements.
REMOVING OIL FILTER ELEMENTS4. Wipe the oil filter housing with a clean rag.5. Install new filter elements, and the filter housing cover.6. Close the filter housing drain valve.7. Fill the oil filter housing and oil cooler with oil; add the oil through the vent plug opening. See the LUBRICATION AND MAINTENANCE CHART for proper oil to use. Do not try to overfill; the excess oil will return through the oil lines to the engine crankcase.8. Install the vent plug.9. Fill the crankcase to the FULL mark on the oil level gauge.10. Prelubricate the engine oil system, if equipped to do so:D349 and D399 Engines: When the START switch is energized, the prelube pump will develop oil pressure in the engine before the starting motors are energized.
PRELUBE PUMP - D349 and D399 EnginesD346, D348, D379 and D398 Engines equipped with a sump pump: The sump pump can be used as a prelube pump by connecting a line from the outlet of the sump pump, through a threeway valve into the oil cooler bypass line.
SUMP PUMP CONNECTED AS PRELUBE PUMP11. Start the engine; reduce engine speed to low idle. Observe the oil pressure gauge reading. If oil pressure does not register, the low oil pressure shut-off control will stop the engine in approximately seven seconds.If the low oil pressure shut-off control stops the engine, investigate the cause and make repairs before attempting to restart.12. Reduce engine speed to low idle. Observe the oil pressure gauge. Oil pressure must be indicated, or shut the engine down and investigate the cause.13. Allow the engine to reach operating temperatures.14. Check the oil level with the engine running. Oil level should be between the ADD mark and the FULL mark. Add oil if necessary.Duplex Oil Filter System
Duplex Oil Filter System
Marine propulsion engines and marine auxiliary electric set engines, which operate under the jurisdiction of international marine classification societies, are required to be equipped with a duplex oil filter system. The duplex oil filter system permits changing oil filter elements without stopping the engine.The filter elements, located in the horizontal oil filter housing, filter the oil during normal operation. The two oil filter cans, located on the right side of the engine, are auxiliary filter elements. At the specified oil filter element change interval, or when the oil filter change indicator is raised approximately one half its maximum height, move the selector lever so as to divert the crankcase oil through the two auxiliary filter elements while the main filter elements are changed.Installing New Main Filter Elements
The main oil filter elements may be changed with the engine running as follows:1. Push down and hold the fill valve to insure that the auxiliary oil filter housing is filled with oil. When the indicated filter pressure stops rising, release the fill valve.
FILL VALVE AND FILTER PRESSURE GAUGES2. Move the selector lever 90° in a clockwise motion to the auxiliary filter position. The crankcase oil is now being filtered through the auxiliary oil filter elements.
SELECTOR LEVER-AUXILIARY FILTER POSITION3. Open the main filter drain valve.4. Remove the vent plug from the right hand end cover and allow the filter housing