77481 1 Mercruiser SHIFT SHAFT, LOWER

Perform the required daily maintenance and other periodic maintenance before starting the engine. Inspect the engine room. This inspection can help prevent major repairs later. See this Operation and Maintenance Manual (Maintenance Section), "Maintenance Interval Schedule".Walk-Around Inspection
For any type of leak (coolant, lube, or fuel) clean up the fluid. If leaking is observed, find the source and correct the leak. If leaking is suspected, check the fluid levels more often than recommended until the leak is found or fixed, or until the suspicion of a leak is proved to be unwarranted.
To obtain maximum service life for your engine, make a thorough inspection before starting the engine. Make a walk-around inspection of the installation. Look for items such as oil or coolant leaks, loose bolts, and trash buildup. Remove any trash. Arrange for repairs, as needed.
The guards must be in the proper place. Repair damaged guards or replace missing guards.
Ensure that the areas around the rotating parts are clear.Air Inlet System
Ensure that the air inlet piping and the air filters are in place.
Ensure that all clamps and connections are secure.
Check the air cleaner service indicator. Clean or replace the air cleaner element when the yellow diaphragm enters the red zone or the red piston locks in the visible position.Note: If the engine is equipped with air shutoff mechanisms, ensure that all air shutoff mechanisms are in the open position prior to starting.Cooling System
Inspect the cooling system for leaks or loose connections.
Inspect the cooling system hoses for cracks and for loose clamps.
Inspect the water pumps for evidence of leaks.
Inspect the fan drive belts for cracks and for deterioration.
Check the coolant level. Add coolant, if necessary. For information on the proper coolant to use, see this Operation and Maintenance Manual, "Fluid Recommendations" (Maintenance Section).Driven Equipment
Note: If the engine is equipped with a system for external support, prepare the system before starting the engine. Perform all prestart checks for the control system.Electrical System
Inspect the wiring for the following conditions:
Loose connections
Wiring that is worn or frayedInspect the alternator belt for cracks and for deterioration.Ensure that the grounds are secure.Fuel System
All valves in the fuel return line must be open before and during engine operation to help prevent high fuel pressure. High fuel pressure may cause filter housing failure or other damage.
Inspect the fuel lines for loose fittings and leaks. Ensure that the fuel lines are properly clamped.
Ensure that fuel is supplied to the engine.If the engine has not been started for several weeks, fuel may have drained from the fuel system. Air may have entered the filter housing. Also, when fuel filters have been replaced, some air space will be left in the filter housing. In these instances, prime the fuel system. For information on priming the fuel system, see this Operation and Maintenance Manual, "Fuel System-Prime" topic (Maintenance Section).Lubrication System
Illustration 1 g00799668
Oil level gauge
(1) "ADD" mark
(2) "FULL" mark
Excessive engine oil will increase oil consumption and result in excessive deposits in the combustion chamber. Do not overfill the engine with oil.
Check the engine crankcase oil level. Maintain the oil level between the "ADD" and "FULL" marks on the "ENGINE STOPPED" side of the oil level gauge. For information on the proper oil to use, see this Operation and Maintenance Manual, "Fluid Recommendations" (Maintenance Section).
Check for leaks at the following components: crankshaft seals, crankcase, oil filters, oil gallery plugs, sensors, and valve covers.
Inspect the tubes, tee pieces, and clamps on the crankcase breathers.Starting System
Inspect the instrument panel and the control panel for good condition.
Reset the shutoff and alarm components.Electric Starting Motor
Disconnect any battery chargers that are not protected against the high current drain that is created when the electric starting motor engages.Inspect the wiring, the electrical cables, and the battery for the following conditions:
Loose connections
Wires that are worn or frayed
Corrosion