• Fast shipping

  • Free help & advice

  • Hassle-free returns

  • Factory direct prices

Welcome Aboard!

FLASHSALE26

Fuel Pump Assembly – Fits Johnson/Evinrude 6-25 HP (Replaces 397839, 388681, 386978)

Regular price $31.00

Worry-free returns

Shop with confidence. If you’re not completely satisfied, eligible items may be returned within the return window, provided they are unused and in original packaging.


If the return is due to our error or a defective item, we’ll make it right.


Please contact us before returning any item.

Delivery and Shipping

Orders are typically processed within 1–2 business days.


U.S. orders usually arrive within 6–15 days, depending on stock location and destination.


International delivery times may vary due to customs processing.


Tracking information will be provided once your order ships.

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 direct-replacement Fuel Pump Assembly – Fits Johnson/Evinrude 6-25 HP outboard motors, designed for 2-stroke models manufactured between 1981 and 1998. It ensures reliable fuel delivery, restoring engine performance and efficiency.

This assembly provides a direct interchange for Johnson/Evinrude part numbers 397839, 388681, 386978, 397274, 777750, 395091, and 391638, as well as aftermarket equivalents like Sierra 18-7350 and Mallory 9-35350.

  • Installs via a direct bolt-on process using the included mounting straps.
  • Features a pulse-driven diaphragm mechanism for consistent fuel flow.
  • Comes as a complete kit with the necessary gasket for a secure seal.

Part Number Matrix

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

Brand Part Number
Johnson/Evinrude 397839
Johnson/Evinrude 388681
Johnson/Evinrude 386978
Johnson/Evinrude 397274
Johnson/Evinrude 777750
Johnson/Evinrude 395091
Johnson/Evinrude 391638
Sierra 18-7350
Mallory 9-35350
EMP 1399-07350
Quicksilver 8M6010285

Engine & Model Compatibility

Confirm your engine model/year in the table below.

Fits various Johnson and Evinrude 2-stroke outboards from 6 to 25 HP.

Brand Model Rated HP Stroke Years OEM Part No. Notes
Johnson/Evinrude Various 6 2-Stroke 1988–1991 397839
Johnson/Evinrude Various 8 2-Stroke 1988–1991 397839
Johnson/Evinrude Various 9.5 2-Stroke 1981–1992 397839
Johnson/Evinrude Various 9.9 2-Stroke 1981–1992 397839
Johnson/Evinrude Various 15 2-Stroke 1981–1992 397839
Johnson/Evinrude Various 25 2-Stroke Up to 1984 397839 For selected models only

Technical Specs

Product Type
Fuel Pump Assembly
Installation
Direct bolt-on with mounting straps
Fuel Type
Gasoline
Connection
Fuel line hose barb fittings
Housing Material
Aluminum/Metal with plastic components
Housing Color
Black/Silver
Fitting Type
Barbed hose connections
Mechanism
Pulse-driven diaphragm type fuel pump

What’s in the Box

  • 1 x Fuel Pump (397839)
  • 2 x Straps/Bands (320107)
  • 1 x Fuel Pump Gasket (303615)

Installation Notes

  1. Disconnect the battery and relieve any pressure from the fuel system.
  2. Place a rag under the old fuel pump to catch any gasoline spills.
  3. Carefully disconnect the fuel inlet, outlet, and pulse hoses, noting their positions.
  4. Unbolt the old pump or release it from its mounting straps.
  5. Clean the mounting surface and install the new gasket.
  6. Mount the new fuel pump, ensuring it is securely fastened.
  7. Reconnect the fuel and pulse hoses to the correct fittings.
  8. Reconnect the battery, prime the fuel system, and check thoroughly for leaks before starting the engine.

Troubleshooting & FAQ

How do I confirm this fuel pump fits my engine?

The best way is to match your original part number to one listed in our Part Number Matrix. You can also check your engine's horsepower and year against the Engine & Model Compatibility table. Always visually compare your old part to our photos.

What are common signs of a failing fuel pump?

Symptoms include difficulty starting, engine sputtering or stalling (especially at high speeds or under load), loss of power, and poor fuel efficiency. A visible leak from the pump housing is also a clear sign of failure.

Is a new gasket included in the package?

Yes, this assembly includes one new fuel pump gasket (part 303615) to ensure a proper seal during installation.

How often should a marine fuel pump be replaced?

There is no fixed replacement interval. It should be inspected regularly and replaced if you notice any signs of wear, leakage, or reduced engine performance.

Is this an OEM part or aftermarket?

This is an aftermarket replacement part, not an original equipment manufacturer (OEM) component. It has been engineered to meet or exceed OEM specifications for fit, form, and function, using comparable materials and manufacturing processes in an ISO 9002 certified facility.

How fast is shipping?

We ship worldwide, and typical transit time is between 5–15 days. Standard shipping is free for most orders, with expedited options available at checkout where applicable.

What is the warranty and return policy?

This product is covered by a 1-year warranty against manufacturing defects under normal marine use. If you encounter an issue, please contact our support team with your order number. Returns of unused items in their original condition are accepted within our standard return window.

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

Payment methods

  • American Express
  • Apple Pay
  • Diners Club
  • Discover
  • Google Pay
  • JCB
  • Maestro
  • Mastercard
  • PayPal
  • Union Pay
  • Visa

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.