Maintenance Schedules-350/377 Mag And Seacore 350/377 Mag; Routine Maintenance - Mercury 350 MAG Manual

Section 5 - Maintenance
Task Interval
Every 300 hours or 3
years
Every 5 years
Maintenance Schedules—350/377 MAG and SeaCore 350/377 MAG

Routine Maintenance

NOTE: Only perform maintenance that applies to your particular power package.
New Bravo sterndrive installations may require as much as 470 mL (16 fl oz)) of gear lube added to the monitor bottle during the
break‑in period (20 hours of running time). It is important to monitor and maintain the gear lube level during the break‑in period.
During the initial drive installation, air may be trapped in the top of the driveshaft housing. This void is filled from the gear lube
monitor during the sterndrive break‑in period. As the air is purged from the sterndrive through the monitor bottle, the lube level in
the bottle will drop.
Task Interval
Each day start
Each day end
Weekly
Page 76
• Check the engine mounts for tightness and torque if necessary.
• Check the electrical system for loose, damaged, or corroded fasteners.
• Inspect the condition of the spark plugs, spark plug wires, and the distributor cap and rotor, if
equipped. Replace as necessary. If the condition of these components is satisfactory at
inspection, repeat inspection every 100 hours or once a year, whichever occurs first.
• Check the cooling system and the exhaust system hose clamps for tightness. Inspect both
systems for damage or leaks.
• Disassemble and inspect the seawater pump and replace worn components.
• On models with closed cooling, clean the seawater section of the closed cooling system. Clean,
inspect, and test the pressure cap.
• Inspect the exhaust system components. If the package was equipped with water shutters
(flapper valves), verify that they are not missing or worn.
• Check the engine alignment.
• Inspect the U‑joints, the splines, the bellows, and check the clamps.
• Lubricate the U‑joint splines and cross bearing, if equipped with a grease fitting.
• Inspect the gimbal bearing for roughness. Replace if necessary. See your certified Mercury
MerCruiser dealer.
• Alpha models and Bravo models: Lubricate the engine coupler.
• Replace the coolant/anitifreeze. Replace every two years if not using extended‑life coolant/
antifreeze.
• Check the engine oil level. (You can extend this interval based on experience with the product.)
• Check the sterndrive gear lube level.
• Check the trim pump oil level.
• Check the power‑assisted steering pump or the compact hydraulic steering fluid level,
depending on the steering system of your model.
• If operating in saltwater, brackish water, or polluted water, flush the seawater section of the
cooling system after each use.
• Check the water inlets for debris or marine growth.
• Check and clean the seawater strainer, if equipped.
• Check the coolant level.
• Inspect the sterndrive anodes and replace if eroded 50% or more.
Maintenance to Be Performed
Maintenance to Be Performed
90-8M0050539 MAY 2011
eng