Mercury - High-Capacity Water-Separating Fuel Filter Kit Fuel System 35-8M0082291. Overview. On boats that pull a lot of fuel-big outboards, twins, maybe even a diesel sterndrive-you can't afford to run a lightweight fuel filter setup. When the filter head can't keep up, the engines stumble, hesitate, or fall flat when you really need them. This high-capacity kit gives you the vessel-mounted head that starts a proper fuel system. Add the fittings that match your hose and the right 10-micron filt