Service your marine fuel filter on a regular basis to avoid fuel delivery problems. Cleaning or replacement of the fuel filter will decrease the risk of blocking the flow of fuel to the engine. A fuel filter is to keep particles of dirt and debris from entering the carburetors or the fuel injection system and clogging the tiny passages of either.
Just a tiny speck of dirt or sand can affect the ability to deliver the proper amount of air fuel/oil to the engine. If a filter becomes clogged, the flow of gasoline will be impeded. Lean fuel mixtures hesitation, stumbling will cause problems in carburetors.
Dirt can also prevent a fuel injector from closing properly. A partially stuck open fuel injector by debris will likely cause the engine to run rich due to the unregulated fuel constantly spraying from the pressurized injector. So all filters should be replaced no less than once a season or every 50 hours of operation.
The type of fuel filter used on your engine will wary with the year and Model. Because of the number of variations it is impossible to accurately give instructions based on model. To determine what filters are utilized by your engine, trace the fuel line from the tank to the fuel pump and then from the pump to the carburetors or throttle body. The majority of engines have a canister-type-in-line water-separating filter.
Most 2.5L and 3.L engines have the filter incorporated into the fuel pump; but may also have an in-line- water-separating filter. Additionally, most carburetor engines will further utilize a small filter/screen in the carburetor.
Most new engines have a factory-installed water separating fuel filter. This type of filter is also available as an accessory for all other engines and should be installed at the earliest convenience. It is not expensive and comes with instructions for installation.
A water-separating filter removes water and other fuel system contaminants before the reach the carburetor and helps minimize potential problems. The presence of water in the fuel will alter the proportion of air/fuel mixture to the lean side. If not corrected it will possible do damage to the pistons, as a resulting from a higher operating temperature.