Re: Mercury four stroke 03 efi stalling.
Start with new spark plugs, and checking the fuel filters and hopefully he has a waterseperating fuel filter that should be checked for water and replaced.
It could also be a sensor failure or minor adjustment to cause the stalling. Getting a diagnostic test done by a dealer and a diagnostic computer, would be a good idea, before the problem gets worse
This is from the Merc 115 OEM service manual about regular maintenance.
Inspection And Maintenance Schedule
To keep your outboard in the best operating condition, it is important that your outboard receive
the periodic inspections and maintenance listed in the Inspection and Maintenance
Schedule. We urge you to keep it maintained properly to ensure the safety of you and your
passengers and retain its dependability.
Before Each Use
1. Check engine oil level.
2. Check that lanyard stop switch stops the engine.
3. Visually inspect the fuel system for deterioration or leaks.
4. Check outboard for tightness on transom.
5. Check steering system for binding or loose components.
6. Visually check steering link rod fasteners for proper tightness.
7. Check propeller blades for damage.
After Each Use
1. Flush out the outboard cooling system if operating in salt or polluted water.
2. If operating in salt water, wash off all salt deposits and flush out the exhaust outlet of the
propeller and gearcase with fresh water.
Every 100 Hours of Use or Once yearly, Whichever occurs first
1. Lubricate all lubrication points. Lubricate more frequently when used in salt water.
2. Change engine oil and replace the oil filter. The oil should be changed more often when
the engine is operated under adverse conditions such as extended trolling.
3. Inspect thermostat visually for corrosion, broken spring, and to determine that the valve
is completely closed at room temperature. If questionable, inspect thermostat as outlined
in Section 4B, Thermostat.
4. Inspect and clean spark plugs.
5. Check engine fuel filter for contaminants.
6. Check engine timing setup.
7. Check corrosion control anodes. Check more frequently when used in salt water.
8. Drain and replace gearcase lubricant.
9. Lubricate splines on the drive shaft.
10. Check power trim fluid.
11. Inspect battery.
12. Check control cable adjustments.
13. Inspect timing belt.
14. Remove engine deposits with Power Tune Engine Cleaner.
15. Check tightness of screws, nuts, and other fasteners.
Every 300 Hours of Use or Three Years
1. Replace water pump impeller (more often if overheating occurs or reduced water pressure
is noted).
Every 400 Hours of Use or Four Years
1. Check and adjust valve clearance if necessary.
