Mercury - Fuel Filter Fuel System Component Internal Carburetor Filter 53336T. Overview. Clean fuel is essential for performance and reliability, and the Mercury Marine 53336T Fuel Filter keeps your MerCruiser running strong. Designed for 3.0L, 4.3L, 5.0L, 5.7L, and 7.4L engines equipped with Rochester 2- or 4-barrel and MerCarb 2-barrel carburetors, this small filter sits inside the carburetor at the fuel line connection. It traps water, dirt, and debris before they reach the engine, protecting