Fuel Pump – Fits Mercury/Tohatsu/Nissan 9.9-30 HP & Johnson/Evinrude 15 HP (Replaces 803529T04, 3H8-04000-1)

Fuel Pump Assembly – Fits Mercury/Tohatsu/Nissan 9.9-30 HP & Johnson/Evinrude 15 HP

This pulse-driven mechanical fuel pump is a reliable aftermarket replacement for a wide range of outboard motors, including 4-stroke models from Mercury/Mariner (9.9-30 HP, 2005–present) and Tohatsu/Nissan (9.9-30 HP, 2002–2018). It also offers limited compatibility with select Johnson/Evinrude 15 HP 2-stroke models.

Engineered to meet or exceed OEM specifications, this pump ensures consistent fuel delivery for optimal engine performance. It serves as a direct replacement for Mercury part 803529T04, Tohatsu/Nissan part 3H8-04000-1, and Johnson/Evinrude part 5041064.

• Installation: Mounts easily with a standard two-bolt system.
• Fuel System: Compatible with standard marine gasoline.
• Complete Kit: Includes the fuel pump, O-ring, and spring clamps for a full replacement.

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 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.

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 Serial Number Guide.

Confirm your engine model/year in the table below.

Mercury/Mariner

Tohatsu/Nissan

Johnson/Evinrude

Technical Specifications

Package Contents

• 1x Fuel Pump Assembly (803529T04/3H8-04000-1)
• 1x O-Ring
• 2x Metal Spring Clamps

Installation Guide

1. Safety First: Disconnect the battery and ensure the engine is cool. Work in a well-ventilated area and have a fire extinguisher nearby.
2. Locate Pump: Identify the existing fuel pump on the engine block.
3. Disconnect Lines: Place a rag under the pump to catch fuel. Carefully disconnect the inlet and outlet fuel lines, noting their orientation.
4. Remove Old Pump: Unbolt the two mounting bolts holding the pump in place and remove the pump and old O-ring/gasket.
5. Install New Pump: Clean the mounting surface on the engine. Place the new O-ring and install the new fuel pump, tightening the bolts evenly.
6. Reconnect Lines: Attach the fuel lines to the correct fittings on the new pump and secure them with the provided spring clamps.
7. Test for Leaks: Reconnect the battery. Prime the fuel system if necessary and check thoroughly for any fuel leaks around the pump and fittings before starting the engine.

Troubleshooting & FAQ

Q: How do I confirm this pump fits my specific engine model?

A: The best way is to match your existing part number to the ones listed in our cross-reference table (803529T04, 3H8-04000-1, 5041064). Additionally, review the compatible engine model tables on this page to ensure your engine's make, HP, and year range are listed.

Q: What are common signs that my fuel pump is failing?

A: Common symptoms of a failing mechanical fuel pump include engine sputtering, loss of power especially at high speeds, difficulty starting, or stalling. You may also notice fuel leaking from the pump body itself.

Q: How often should I replace my fuel pump?

A: There is no fixed replacement interval, but fuel pumps are a critical wear item. Consider a replacement as part of preventative maintenance, especially on older engines or if you experience any performance issues.

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.