FUSCH Electric Low-Pressure Marine Fuel Pump for Mercury Mercruiser 4.3L/5.0L/5.7L – 8–10 PSI, direct-fit replacement

This precision-built pump is designed for owners and technicians who need a dependable, OEM-standard replacement for older boat fuel pumps. Constructed from metal and ABS components and produced to match original equipment specifications, the unit replaces part numbers such as Mercruiser 861155A3, Mallory 935432, and Sierra 18-8868. It arrives with sealing washers and an electrical connector plug so you can reinstall it with minimal fuss.

How do I know this pump fits my Mercury/Mercruiser carbureted engine?

Compatibility centers on carbureted engine models and years. This pump fits Mercruiser MCM/MIE 4.3L V6 and 5.0L V8 Gen+ applications and many 5.7L (350 ci) carbureted engines from typical model years listed by OEM references.

• Replaces OEM numbers 861155A3, 861155A2, Mallory 935432 and Sierra 18-8868.
• Commonly used on 4.3L 262 (1998), 5.0L 305 (2000), 5.7L 350 (2000) carbureted engines.
• Checks: threaded small end and carburetor-based fuel system required.

What fuel pressure and engine types is this pump designed for?

This is a low pressure electric pump engineered to supply approximately 8–10 PSI, which matches the pressure needs of most marine carburetors. It is not suitable for fuel-injected systems, which require higher pressure and a different pump design.

• Rated output: low pressure, about 8–10 PSI for carburetors.
• Not compatible with fuel-injected engines or high-pressure systems.
• Small threaded inlet/outlet — a visual check distinguishes it from injection pumps.

What materials, build quality, and accessories are included?

The pump housing combines metal and durable ABS components to meet OEM-style standards for corrosion resistance and mechanical stability in marine environments. Each unit ships with the necessary small parts to simplify installation and ensure a tight seal at fittings.

• Construction: metal plus ABS for durability and marine resistance.
• Manufactured to OEM tolerances for direct-fit replacement.
• Package includes tight-seal washers and an electrical connector plug.

How should I install and verify correct operation?

Installation is straightforward for anyone familiar with marine fuel systems: mount the pump using existing bolt points, connect the electrical plug and hoses, and check for leaks. After installation, confirm fuel pressure at the carburetor and inspect all seals while running the engine briefly.

• Mount to original bracket or compatible retrofit location.
• Use provided washers and the connector plug for a secure electrical and fuel seal.
• Verify ~8–10 PSI at carburetor and check for leaks before full operation.

Who is this for: boat owners, marine mechanics, and restoration shops maintaining older Mercury/Mercruiser V6 and V8 carbureted engines that require a reliable low pressure electric fuel pump. If your vessel uses a carburetor and your current pump shows wear, leaks, weak flow, or matches the replaced OEM numbers, this FUSCH unit provides a practical, OEM-grade replacement. Do not buy this pump for fuel-injected engines; choose a high-pressure injection pump for those applications.