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

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

This fuel pump assembly is a direct-fit replacement for Tohatsu, Nissan, Mercury, and Mariner outboard motors. It is designed to meet or exceed original equipment specifications for reliable fuel delivery.

This component fits Tohatsu/Nissan 4-9.8 HP 4-stroke engines from 2002–2014 and Mercury/Mariner 4-6 HP 4-stroke engines. It is a direct replacement for Tohatsu part numbers 3H6-04000-0M through 3H6-04000-7M and Mercury part numbers 803529T, 803529T01, 803529T02, 803529T03, and 803529T06.

• Installation: Direct OEM Replacement
• Housing Material: Metal
• Compatible Fuel Type: Gasoline

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.

Technical Specifications

Package Contents

1 x Fuel Pump Assembly (3H6-04000/803529T)

Installation Guide

1. Disconnect the battery and relieve any pressure in the fuel system.
2. Place absorbent rags around the old fuel pump to catch any spilled fuel.
3. Carefully disconnect the fuel inlet and outlet lines from the pump.
4. Remove the mounting bolts that secure the fuel pump to the engine block.
5. Take out the old pump and thoroughly clean the mounting surface, removing any old gasket material.
6. Compare the new pump to the old one to ensure a perfect match.
7. Position the new fuel pump and install it with the new gasket.
8. Tighten the mounting bolts evenly to the manufacturer's recommended torque.
9. Securely reconnect the fuel lines to the new pump.
10. Reconnect the battery.
11. Prime the fuel system according to your engine's manual and carefully check all connections for leaks.
12. Start the engine, let it idle, and confirm smooth operation without any leaks.

Troubleshooting & FAQ

Q: How do I know if this fuel pump fits my Tohatsu or Mercury engine?

A: This pump fits specific Tohatsu/Nissan 4-9.8 HP 4-stroke models (2002-2014) and Mercury/Mariner 4-6 HP 4-stroke outboards. Please refer to the "Compatible Engine Models" table and cross-reference your engine's model and year. It directly replaces Tohatsu part numbers starting with 3H6-04000 and Mercury parts like 803529T.

Q: What are the signs of a failing fuel pump?

A: Common symptoms include difficulty starting the engine, stalling at low speeds, rough idling, engine hesitation during acceleration, or a complete loss of power. If you notice these issues, your fuel pump may need inspection or replacement.

Q: Is this a complete assembly?

A: Yes, this is a complete fuel pump assembly. The package includes one pump, as shown in the images. Gaskets or additional fittings are not included unless specified in the package contents.

Q: My engine model is listed, but the part looks different. What should I do?

A: Do not install the part. Manufacturers sometimes make mid-year design changes. Please review the "Important Notes" and verify that the product images and specifications exactly match your original part before purchasing.

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.