Re: Mercruiser Tune-up?
1. Install a water separating fuel filter between the fuel tank and the fuel pump.
2. Replace the filters in the fuel pump and carb.
3. New spark plugs, new cap and rotor.
4. Do a tunup now while everything works, and each time you tune it up. Then you have a base line and can pinpoint problems when they happen later on down the line.
Check the timing, and advance timing to make sure they are to specs. along with idle rpm speed, and carb mixture if needed.
5. Follow all procedures in the OEM service manual.
6. Have you been keeping up with the yearly impeller, bellows, alignment checks, kubrication and other preventive maintenance mentioned in your owners manual?