Fuel Pump – Fits Mercury/Mariner 4-6 HP & Tohatsu/Nissan 4-9.8 HP 4-Stroke (Replaces 803529T06, 3H6-04000-7)

Fuel Pump – Fits Mercury/Mariner 4-6 HP & Tohatsu/Nissan 4-9.8 HP 4-Stroke (Replaces 803529T06, 3H6-04000-7)

This fuel pump assembly is designed for reliable performance in a range of 4-stroke outboard motors, including Mercury/Mariner models from 4 HP to 6 HP and Tohatsu/Nissan models from 4 HP to 9.8 HP, manufactured from 2003 to the present.

It serves as a direct replacement for multiple OEM part numbers, ensuring a precise fit and straightforward installation. This component is manufactured in an ISO9002-certified facility to meet or exceed original equipment specifications, providing a dependable solution for maintaining your engine's fuel system.

• Installation Method: Direct OEM-style replacement
• Compatible Fuel Type: Gasoline
• Package Contents: Includes one (1) complete fuel pump assembly

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.

Tohatsu/Nissan

Mercury/Mariner

Technical Specifications

Package Contents

• 1 x Fuel Pump Assembly (3H6-04000-7/803529T06)

Installation Guide

1. Safety First: Disconnect the battery and work in a well-ventilated area away from sparks or flames.
2. Relieve Pressure: Safely relieve any pressure in the fuel system according to your engine's service manual.
3. Prepare for Spills: Place absorbent rags or a suitable container below the fuel pump to catch any spilled fuel.
4. Disconnect Lines: Carefully disconnect the inlet and outlet fuel lines from the pump. Note their orientation.
5. Remove Old Pump: Unbolt and remove the old fuel pump from the engine block.
6. Clean Surface: Thoroughly clean the mounting surface on the engine block, removing any old gasket material or debris.
7. Install New Pump: Position the new fuel pump (with a new gasket, if required) onto the engine block.
8. Secure Pump: Hand-tighten the mounting bolts, then torque them to the manufacturer's specified value. Do not overtighten.
9. Reconnect Lines: Securely reattach the fuel inlet and outlet lines to the correct ports on the new pump.
10. Final Checks: Reconnect the battery. Prime the fuel system using the primer bulb until firm.
11. Inspect for Leaks: Start the engine and carefully inspect the pump and all connections for any signs of fuel leaks before use.

Troubleshooting & FAQ

How do I confirm this fits my engine?
To ensure compatibility, compare your engine's model and year against the "Compatible Engine Models" table. It's also critical to cross-reference your existing fuel pump's part number with the numbers listed in our "Part Number Cross-Reference" section, such as 803529T06 for Mercury/Mariner or 3H6-04000-7 for Tohatsu/Nissan.

What are the common signs of a failing fuel pump?
Symptoms of a faulty fuel pump often include difficulty starting the engine, stalling, sputtering at high speeds, a noticeable loss of power, or poor acceleration. If your outboard is experiencing these issues, the fuel pump may be the cause.

OEM vs. Aftermarket?
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.

How fast do you ship and how much does it cost?
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.

What is your warranty and return policy?
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.