Mercury - Carburetor Gasket Set Fuel System Service Composite Gasket Material FK10023. Overview. Anyone who's spent enough hours on the water knows how much trust we put in the small parts-the ones you rarely notice until something feels "off." A smooth-running two-stroke has a rhythm you can sense through the helm, and when that rhythm slips, you feel it immediately. Installing a reliable Mercury Marine part like the FK10023 gasket set brings back that steady confidence. It's the peace of mind