Electric High Pressure Fuel Pump – Fits MerCruiser V6 & V8 EFI/MPI (Replaces 861156A1, 807949A1)

$32.99 $52.00

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Electric High Pressure Fuel Pump – Fits MerCruiser V6 & V8 EFI/MPI (Replaces 861156A1, 807949A1) is backordered and will ship as soon as it is back in stock.

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If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This is a high-quality aftermarket Electric High Pressure Fuel Pump designed for Mercury MerCruiser V6 and V8 EFI/MPI engines from approximately 1988 through the 2000s. It is engineered for use with electronic fuel injection (EFI/MPI) systems only and is not compatible with carbureted engines.

This component is a direct interchange for Mercury Marine part numbers 861156A1 and 807949A1, as well as Sierra 18-35433, Mallory 935433, and Airtex E11004.

Installation: Mounts externally as an in-line pump, not for in-tank use.
Engine Compatibility: Exclusively for modern EFI/MPI engines.
Construction: Features a durable aluminum housing with one threaded inlet and one non-threaded outlet with a snap fitting.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand	Part Number
Mercury Marine	861156A1
Mercury Marine	807949A1
Sierra	18-35433
Mallory	935433
Airtex	E11004

Engine & Model Compatibility

Confirm your engine model/year in the table below.

The following MerCruiser models are compatible with this fuel pump. Please verify your specific application and part number before ordering.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
MerCruiser	4.3L EFI/TBI/MPI Alpha/Bravo	4.3L	4-Stroke	1988–	861156A1	Non-threaded outlet
MerCruiser	5.0L EFI/MPI Alpha/Bravo	5.0L	4-Stroke	1988–	861156A1	Non-threaded outlet
MerCruiser	5.7L EFI/MPI Alpha/Bravo/Horizon/MIE/Ski	5.7L	4-Stroke	1988–	861156A1	Non-threaded outlet
MerCruiser	350 MPI Alpha/Bravo/Horizon/MIE/Ski	350	4-Stroke	1988–	861156A1	Non-threaded outlet
MerCruiser	454 MPI Bravo & Horizon	7.4L	4-Stroke	1988–	861156A1	Non-threaded outlet
MerCruiser	502 MPI	8.2L	4-Stroke	1988–	861156A1	Non-threaded outlet
MerCruiser	7.4L MPI Bravo & MIE	7.4L	4-Stroke	1988–	861156A1	Non-threaded outlet
MerCruiser	8.1L/8.2L MIE MPI	8.1L/8.2L	4-Stroke	1988–	861156A1	Non-threaded outlet
MerCruiser	MX6.2L MPI Alpha/Bravo/Horizon & MIE	6.2L	4-Stroke	1988–	861156A1	Non-threaded outlet
MerCruiser	Black Scorpion	-	4-Stroke	1988–	861156A1	Non-threaded outlet
MerCruiser	Scorpion 377 Sterndrive Racing	377	4-Stroke	1988–	861156A1	Non-threaded outlet

Technical Specs

Product Type: Electric High Pressure Fuel Pump
Installation: In-line (not in-tank)
Fuel Type: Gasoline
Connection: One threaded end, one non-threaded end with snap fitting
Housing Material: Aluminum
Housing Color: Silver/Metallic
Dimensions: 22.5 x 14.0 x 8.0 cm
Weight: 0.65 kg (1.43 lb)
Fitting Type: Barb connections
Other Technical Attributes: IMPORTANT: For EFI/MPI engines only. Not compatible with carbureted engines.

What’s in the Box

1 x Electric Fuel Pump (861156A1)

Installation Notes

Disconnect the boat's battery before beginning work.
Carefully relieve the pressure from the fuel system according to your engine's service manual.
Place absorbent rags under the fuel line connections to catch any spills.
Disconnect the fuel lines and the electrical connector from the old pump.
Remove the mounting hardware and take out the old fuel pump.
Install the new pump in the same location and orientation as the original.
Securely reconnect the fuel lines and the electrical connector.
Reconnect the battery.
Prime the fuel system by cycling the ignition key (without starting the engine) a few times.
Thoroughly inspect all connections for leaks before and after starting the engine.

Troubleshooting & FAQ

How do I know if this fuel pump fits my MerCruiser engine?

This pump fits most MerCruiser V6 and V8 EFI/MPI engines from 1988 to the 2000s. The best way to confirm fitment is to verify your engine model and original part number (e.g., 861156A1, 807949A1) against our compatibility tables. This part is not for carbureted engines.

What are the signs of a failing high-pressure fuel pump?

Common symptoms include engine hesitation, sputtering at high speeds, loss of power, difficulty starting, or a noticeable whining noise coming from the pump's location. A fuel pressure test is the most reliable diagnostic method.

Is this an in-tank or in-line fuel pump?

This is an external, in-line high-pressure fuel pump. It is designed to be mounted outside of the fuel tank and is not a substitute for an in-tank pump.

What's the difference between this and a carbureted engine's fuel pump?

This is a high-pressure pump designed for Electronic Fuel Injection (EFI/MPI) systems, which require significantly higher fuel pressure than low-pressure pumps used in carbureted engines. They are not interchangeable.

Do I need any special tools for installation?

Standard hand tools are required. A fuel pressure gauge is essential for safely relieving system pressure before you start and for verifying correct pressure after installation. Line wrenches for fuel fittings are also highly recommended to prevent stripping.

What is the recommended replacement interval?

Fuel pumps do not have a fixed service interval and are typically replaced when they fail or show signs of performance degradation. Engine hours, fuel quality, and operating conditions all affect the lifespan of a fuel pump.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
This is an aftermarket replacement, not an OEM component.
Professional installation is recommended for safety and performance.

About Sea Sierra

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