Fuel Pump – Fits Johnson/Evinrude 4.5–25 HP (Replaces 397839)

Fuel Pump Assembly – Fits Johnson/Evinrude 4.5–25 HP (Replaces 397839)

This fuel pump is a direct-fit replacement for a wide range of Johnson/Evinrude outboard motors from 4.5 HP to 25 HP, manufactured between 1968 and 1992. It is designed to meet or exceed original equipment specifications, ensuring reliable fuel delivery for both 2-stroke and 4-stroke engines.

It also serves as a replacement for Mercury fuel pump OEM# 878965, though specific model applications are not fully documented. This component is produced in an ISO9002 certified factory, guaranteeing quality and performance.

• Direct Replacement: Installs without modifications, replacing numerous OEM part numbers.
• Compatibility: Designed for gasoline-fueled outboard engines.
• Complete Kit: Includes the fuel pump assembly, a new gasket, and two cable ties for a full installation.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below. For Johnson/Evinrude owners, here’s a guide to help you identify your engine’s serial/model: Johnson/Evinrude Serial Number Guide.

Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Technical Specifications

Package Contents

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

Installation Guide

1. Safety First: Disconnect the battery and ensure the engine is cool. Work in a well-ventilated area away from sparks or open flames.
2. Relieve Fuel Pressure: Carefully relieve any pressure from the fuel system according to your service manual's instructions.
3. Disconnect Lines: Place a rag under the fuel pump to catch spills. Disconnect the incoming and outgoing fuel lines from the pump.
4. Remove Old Pump: Unbolt and remove the old fuel pump from the engine block. Note the orientation of the fittings.
5. Clean Surface: Clean the mounting surface on the engine, removing any old gasket material.
6. Install New Pump: Install the new fuel pump using the new gasket provided. Ensure bolts are tightened to the manufacturer's specified torque.
7. Reconnect Lines: Securely reconnect the fuel lines to the new pump.
8. Final Checks: Reconnect the battery. Prime the fuel system and check thoroughly for any leaks before starting the engine.

Troubleshooting & FAQ

Q: How do I confirm this part fits my engine?
A: The best method is to match your existing part number to one of the cross-reference numbers listed, such as Johnson/Evinrude 397839 or Sierra 18-7350. Also, check your engine's HP and year against the compatibility table. This pump fits a wide range of Johnson/Evinrude models from 4.5 HP to 25 HP made between 1968 and 1992.

Q: What is the correct horsepower range? Some sources show 4.5-15 HP, others up to 25 HP.
A: Our data shows the most commonly cited range is 4.5–15 HP. However, some reliable sources confirm compatibility up to 25 HP for the same part number. We recommend verifying your specific engine's OEM part number to be certain. If your 20 or 25 HP motor uses one of the listed part numbers, this pump will fit.

Q: Does this fit my Mercury outboard?
A: This fuel pump replaces Mercury OEM part number 878965. However, specific Mercury engine models and years that use this part are not well-documented. If your current pump is stamped with 878965, this part will serve as a direct replacement.

Q: OEM vs. Aftermarket?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.