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Fuel Pump – Fits Johnson/Evinrude 4.5-25HP, Mercury (Replaces 397839, 391638, 395091, 397274, 878965)

Regular price $31.20

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 aftermarket Fuel Pump – Fits Johnson/Evinrude 6HP, 8HP, 9.9HP, 15HP is engineered for a broad range of Johnson/Evinrude 2-stroke and 4-stroke outboard engines from 4.5 HP to 25 HP, generally covering models from 1968–1992. It serves as a reliable, direct-fit replacement to restore fuel system performance.

It provides a direct interchange for Johnson/Evinrude parts 397839, 397274, 391638, and 395091; Mercury 878965; Sierra 18-7350; Mallory 9-35350; EMP 1399-07350; Redline RL7350; and Quicksilver 8M6010285.

  • Designed for simple, direct OEM replacement installation.
  • Features a durable diaphragm-type mechanism housed in a metal and composite body.
  • Manufactured in an ISO9002 certified facility for quality assurance.

Part Number Matrix

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

Brand Part Number
Johnson/Evinrude 397839
Johnson/Evinrude 391638
Johnson/Evinrude 395091
Johnson/Evinrude 397274
Mercury 878965
Sierra 18-7350
Mallory 9-35350
EMP 1399-07350
Redline RL7350
Quicksilver 8M6010285

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Johnson/Evinrude owners: This pump is confirmed to fit 4.5 HP, 6 HP, 8 HP, 9.9 HP, and 15 HP models from 1968 to 1992. Some sources suggest compatibility extends to 20 HP and 25 HP models in the same year range.

For Mercury owners: While this part cross-references to Mercury OEM #878965, a detailed list of compatible Mercury models is not available. Please verify visually before ordering.

Brand Model Rated HP Stroke Years OEM Part No. Notes
Johnson/Evinrude Various 4.5 2-Stroke & 4-Stroke 1968–1992 397839
Johnson/Evinrude Various 6 2-Stroke & 4-Stroke 1968–1992 397839
Johnson/Evinrude Various 8 2-Stroke & 4-Stroke 1968–1992 397839
Johnson/Evinrude Various 9.9 2-Stroke & 4-Stroke 1968–1992 397839
Johnson/Evinrude Various 15 2-Stroke & 4-Stroke 1968–1992 397839
Johnson/Evinrude Various 20 2-Stroke & 4-Stroke 1968–1992 397839 Compatibility mentioned in some sources
Johnson/Evinrude Various 25 2-Stroke & 4-Stroke 1968–1992 397839 Compatibility mentioned in some sources
Mercury Various 878965 Specific models not documented

Technical Specs

Product Type
Outboard Engine Fuel Pump
Installation
Direct OEM replacement
Fuel Type
Gasoline
Connection
Two barbed hose fittings
Housing Material
Metal base with plastic/composite top
Housing Color
Black with metal accents
Weight
0.25 kg (0.55 lbs) approximate
Fitting Type
Barbed hose connectors
Warranty
Varies by manufacturer (Sierra: 1-year, JLM Marine: manufacturer warranty)
Other Technical Attributes
Diaphragm-type fuel pump; Produced in ISO9002 certified factory (JLM Marine)

What’s in the Box

  • 1 x Fuel pump assembly (397839)
  • 1 x Gasket (0303615)
  • 2 x Cable ties (select aftermarket packages)

Installation Notes

  1. Disconnect the battery and relieve any pressure from the fuel system.
  2. Carefully label and disconnect the inlet and outlet fuel lines from the old pump.
  3. Unbolt and remove the old fuel pump from the engine block.
  4. Thoroughly clean the mounting surface to ensure a proper seal.
  5. Place the new gasket onto the engine block, aligning it with the mounting holes.
  6. Mount the new fuel pump, ensuring it is seated correctly against the gasket, and tighten the bolts to the manufacturer's specified torque.
  7. Reconnect the fuel lines to the correct barbed fittings on the new pump.
  8. Reconnect the battery.
  9. Prime the fuel system according to your engine's service manual and inspect carefully for any leaks before starting the engine.

Troubleshooting & FAQ

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

The best way to confirm fitment is to check your original part number against the list in our Part Number Matrix. Also, compare the photos in this listing to your old part. While this pump fits many Johnson/Evinrude models from 1968–1992, verifying these details is crucial.

What are the common signs of a failing fuel pump?

Symptoms of a bad fuel pump include difficulty starting the engine, engine sputtering or stalling (especially at high speeds), loss of power, and poor fuel efficiency. You may also notice the engine running lean.

How often should this part be replaced?

There is no fixed replacement interval for this type of fuel pump. It should be replaced when it shows signs of failure. Regular inspection of fuel lines and checking for leaks can help prevent issues.

Is the included gasket all I need for installation?

Yes, the package includes one new gasket (0303615) required for mounting the pump to the engine block. No other gaskets are typically needed for this specific replacement job.

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.

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