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Low Pressure Electric Fuel Pump – Fits MerCruiser 4.3L, 5.0L, 5.7L (Replaces 861155A3)

Sale price $210.57 Regular price $336.00
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Low Pressure Electric Fuel Pump – Fits MerCruiser 4.3L, 5.0L, 5.7L (Replaces 861155A3) is backordered and will ship as soon as it is back in stock.


Worry-free returns

You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

Delivery and Shipping

Free standard shipping on all orders under 1 KG

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 Low Pressure Electric Fuel Pump is a direct-fit replacement for carbureted MerCruiser 4.3L V6, 5.0L V8, and 5.7L V8 engines from model year 1998 and newer. It is engineered to restore original fuel system performance and reliability, ensuring your engine receives a consistent fuel supply at the correct pressure.

Serves as a direct interchange for Mercury MerCruiser part numbers 861155004, 861155A2, 861155A3, and 861155A6, as well as aftermarket references Sierra 18-8867, EMP 1397-97000, and YOHIB OEN 861155A3.

  • Designed for simple inline installation.
  • Compatible with gasoline fuel systems (not for fuel-injected engines).
  • Includes a pre-installed multi-pin electrical connector for plug-and-play setup.

Part Number Matrix

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

Brand Part Number
Mercury MerCruiser 861155004
Mercury MerCruiser 861155A2
Mercury MerCruiser 861155A3
Mercury MerCruiser 861155A6
Sierra 18-8867
EMP 1397-97000
YOHIB OEN 861155A3

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For MerCruiser models, this pump is specifically for carbureted V6 and V8 engines (Gen+) manufactured in 1998 or later. It is not compatible with EFI, MPI, or other fuel-injected systems.

Brand Model Rated HP Stroke Years OEM Part No. Notes
MerCruiser 4.3L Alpha/Bravo (262 CID - Gen+) 4.3L V6 4-Stroke 1998 and up 861155A3 For carbureted engines only
MerCruiser 4.3LH (Gen+) (4 BBL.) GM 262 V-6 4.3L V6 4-Stroke 1998 and up 861155A3 For carbureted engines only
MerCruiser 4.3L CARB ALPHA/BRAVO 4.3L V6 4-Stroke 1998 and up 861155A3 For carbureted engines only
MerCruiser 4.3L Alpha 4V 4.3L V6 4-Stroke 1998 and up 861155A3 For carbureted engines only
MerCruiser 5.0L Alpha/Bravo Gen+ 5.0L V8 4-Stroke 1998–2001 861155A3 For carbureted engines only
MerCruiser 5.0L (2 BBL.) GM 305 V-8 5.0L V8 4-Stroke 1998–2001 861155A3 For carbureted engines only
MerCruiser 5.7L Alpha/Bravo Gen+ 5.7L V8 4-Stroke 1998–2001 861155A3 For carbureted engines only
MerCruiser 5.7L CARB ALPHA/BRAVO 5.7L V8 4-Stroke 1998 and up 861155A3 For carbureted engines only
MerCruiser 5.7L CARB (MIE) (GEN+) 5.7L V8 4-Stroke 1998 and up 861155A3 For carbureted engines only
MerCruiser 5.7L CARB INBOARD 5.7L V8 4-Stroke 1998 and up 861155A3 For carbureted engines only
MerCruiser 5.7L CARB MIE 5.7L V8 4-Stroke 1998 and up 861155A3 For carbureted engines only
MerCruiser 5.7L CARB SKI 5.7L V8 4-Stroke 1998 and up 861155A3 For carbureted engines only
MerCruiser 5.7L COMPETITION SKI ENGINE (GEN+) 5.7L V8 4-Stroke 1998 and up 861155A3 For carbureted engines only
MerCruiser 350 MAG MPI SKI 5.7L V8 4-Stroke 1998 and up 861155A3 For carbureted engines only
MerCruiser 383 MAG STROKER 6.3L V8 4-Stroke 1998 and up 861155A3 For carbureted engines only

Technical Specs

Product Type
Low Pressure Electric Fuel Pump
Installation
Inline
Fuel Type
Gasoline (not for fuel injected engines)
Connection
Multi-pin electrical connector
Housing Material
Aluminum
Housing Color
Silver/Natural
Dimensions
22.0 × 14.0 × 8.5 cm
Weight
0.671 kg (1.48 lb)
Fitting Type
Threaded inlet and outlet
Working Pressure
8-10 PSI
Voltage
12V DC

What’s in the Box

  • 1 x Fuel Pump Electric (861155A3)
  • 1 x Lead Wires with Multi-pin Connector
  • 1 x Fittings (805027)
  • 1 x O-Ring (0.530 x 0.082 in) (805062)
  • 1 x O-Ring (0.301 x 0.070 in) (805063)

Installation Notes

  1. Disconnect the boat's battery.
  2. Safely relieve any pressure from the fuel system. Place absorbent rags under the fuel line connections.
  3. Carefully disconnect the fuel lines from the old pump. Note the inlet and outlet orientation.
  4. Unplug the electrical connector and unbolt the old pump from its mounting location.
  5. Install the new fuel pump, ensuring it is securely mounted.
  6. Connect the fuel lines to the new pump using the supplied fittings and O-rings. Ensure connections are tight to prevent leaks.
  7. Plug in the new electrical connector.
  8. Reconnect the battery.
  9. Turn the ignition key to the "On" position several times (without starting the engine) to prime the system.
  10. Thoroughly inspect all connections for any signs of fuel leaks before starting the engine.

Troubleshooting & FAQ

How do I confirm if this pump fits my engine?

Verify your complete engine model, serial number range, and year against the compatibility chart in this listing. This pump is only for carbureted MerCruiser 4.3L, 5.0L, and 5.7L engines from 1998 and later. Do not rely on visual comparison alone.

Is this pump for fuel-injected (EFI/MPI) engines?

No. This is a low-pressure pump designed exclusively for carbureted engines, operating at 8-10 PSI. Fuel-injected systems require high-pressure pumps and will not function with this part.

What are common signs of a failing fuel pump?

Symptoms include difficulty starting, engine sputtering or stalling (especially under load or at high speeds), loss of power, and unusual whining noises from the fuel tank area. A fuel pressure test is the most reliable diagnostic method.

What makes this different from the OEM MerCruiser pump?

Functionally, it is a direct replacement designed to meet or exceed original specifications for pressure, flow, and fit. The primary difference is that it is an aftermarket part, offering a better value without sacrificing quality.

Is any special maintenance required?

No specific maintenance is required for the pump itself. However, to ensure its longevity, it's critical to maintain a clean fuel system. Regularly replace your boat's fuel filter(s) according to the manufacturer's service schedule.

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

  • Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
  • Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
  • Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

Payment & Security

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