Yeoflagtrade Electric Fuel Pump Replacement 861155A3 — Direct-Fit Dual-Line Low-Pressure for Mercruiser 4.3L/5.0L/5.7L

The Yeoflagtrade 861155A3 electric fuel pump is a direct-fit, low-pressure replacement engineered to restore reliable fuel delivery for Mercury Mercruiser 4.3L, 5.0L and 5.7L carbureted marine engines.

Built to match the dual-line layout used on many older MerCruiser systems, this pump replaces OE numbers including 861155A3, 861155-2 and 18-8868. It is designed for carbureted V6 and V8 powerplants commonly found in recreational boats, offering an aftermarket option when the original pump shows wear, leaks, or dropping pressure. Yeoflagtrade emphasizes durability with components rated for extended service life so you can spend more time on the water and less time troubleshooting fuel delivery.

How does this pump fit my Mercury MerCruiser engine?

The 861155A3 model is made to be a direct replacement for the low-pressure, dual-line fuel pumps used on late-1990s and early-2000s Mercruiser carbureted engines. Verify fitment using your engine year, model and the OE part numbers before purchase to ensure compatibility.

• Compatible with 4.3L V6 (262 ci), 5.0L V8 (305 ci) and many 5.7L (350 ci) carbureted engines.
• Replaces OEM numbers: 861155A3, 861155-2, 18-8868, 935432 and variations.
• Dual-line design mirrors factory transfer pump layout for straightforward installation.
• Check your boat’s year/make/model and engine block stamping for confirmation.

What are the performance and durability features of this replacement pump?

Yeoflagtrade engineered this pump to deliver consistent low-pressure flow suitable for carburetor fuel systems. Internal components are selected to resist marine fuel exposure and to provide many hours of dependable operation under normal boating conditions.

• Low-pressure output tuned for carbureted MerCruiser engines to maintain steady fuel feed.
• Dual-line configuration supports common fuel transfer setups on these engines.
• Construction targeted for long service life—engineered for extended operating hours.
• Manufactured to replace known OE part numbers for easier sourcing and interchangeability.

How easy is installation and what should I prepare for?

Installation is generally straightforward for a mechanically inclined owner or marine technician because the pump uses the factory mounting and dual-line connections. Basic tools and attention to fuel safety are required; replace fuel lines and clamps if they show age or damage.

• Mounts using the same bolt pattern as original MerCruiser pumps—no custom brackets needed in most cases.
• Dual inlet/outlet lines attach to standard hose fittings; use marine-rated hose clamps.
• Turn off battery power and relieve fuel pressure before beginning work for safety.
• Inspect adjacent fuel lines and fittings; replace brittle hoses to prevent leaks.

Will this pump work with modern fuel blends and accessories?

The pump is intended for conventional gasoline blends typical of recreational marine use and for carbureted systems without high-pressure fuel injection. If you use ethanol-blended fuels, verify compatibility of hoses and seals; upgrading to ethanol-resistant components is recommended when needed.

• Designed for carburetor systems; not for high-pressure EFI systems.
• Use ethanol-compatible hoses and seals if running ethanol-blended fuels.
• Avoid exposure to solvents or fuels outside typical marine gasoline specifications.
• Check local marine regulations regarding fuel-handling components and replacements.

Who is this for: The Yeoflagtrade 861155A3 pump is aimed at owners, mechanics, and boatyards maintaining older MerCruiser-equipped boats that rely on carbureted 4.3L, 5.0L or 5.7L engines. It suits anyone needing a dependable, OE-interchange replacement—particularly boaters restoring older vessels or replacing worn fuel pumps to restore reliable starting and running. Always confirm compatibility with your engine year and OE part numbers before ordering, and consider professional installation if you are not comfortable with fuel-system work.