Mercury - Quicksilver Quick Disconnect Fuel Line Fitting Fuel System Component Brass and Composite 13563Q7. Overview. Every boater knows that your engine's only as reliable as the fuel system feeding it. The Mercury Marine 13563Q7 Quicksilver Quick Disconnect Fuel Line Fitting is one of those small but essential parts that keeps that connection solid and leak-free. Built for Mercury, Mariner, and Force outboards, this fitting connects your portable fuel tank to your motor with a clean, secure sn