Quicksilver - Low-Pressure Fuel Boost Pump MerCruiser Fuel System Marine-Grade Construction 861155A3. Overview. If you've ever felt an engine hesitate as you throttle up, you know how unsettling it can be. Smooth, confident fuel delivery is the heartbeat of a good boating day, and this Quicksilver fuel boost pump is designed to bring that steady rhythm back. It's one of those Mercury Marine parts you install and immediately appreciate - not because it draws attention to itself, but because your