Fuel Pump Assembly – Fits Mercury/Tohatsu/Mariner 4-30HP 4-Stroke Outboards (Replaces 803529T04, 3H6-04000-7)

Fuel Pump Assembly – Fits Mercury/Tohatsu/Mariner 4-30HP 4-Stroke Outboards (Replaces 803529T04, 3H6-04000-7)

This mechanical fuel pump assembly is a direct-fit replacement for a range of Mercury Marine/Mariner 9.9–30HP 4-Stroke (2003–2016) and Tohatsu/Nissan 4–9.8HP 4-Stroke (2002–2014) outboard engines. It is designed to meet or exceed OEM specifications for reliable fuel delivery.

Replaces Mercury part numbers 803529A04 and 803529T04; Tohatsu numbers 3H6-04000-0, 3H6-04000-1, and 3H6-04000-7; Mariner 803529T04; Nissan numbers 3H6040000M through 3H6040007M; Sierra 18-8865; and GLM 40670.

• Installation: Engine-mounted for straightforward replacement.
• Fuel Compatibility: Designed for use with gasoline.
• Package Contents: Includes one 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.

For Tohatsu and Nissan owners, please confirm your model and year in the table below.

Mercury/Mariner Models

Tohatsu/Nissan Models

Technical Specifications

Package Contents

• 1 x Fuel Pump Assembly (803529T04/3H6-04000-7)

Installation Guide

1. Safety First: Disconnect the battery and ensure you are working in a well-ventilated area. Have a fire extinguisher nearby.
2. Locate Pump: Find the existing fuel pump on the side of the engine block.
3. Prepare for Spillage: Place a clean rag or container below the fuel pump to catch any fuel that may spill.
4. Disconnect Hoses: Carefully loosen the clamps and disconnect the fuel inlet and outlet hoses from the pump.
5. Remove Old Pump: Unscrew the mounting bolts that secure the pump to the engine. Gently remove the old pump and any existing gasket.
6. Clean Surface: Thoroughly clean the mounting surface on the engine, 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 and secure it with the mounting bolts. Tighten the bolts to the manufacturer's specified torque.
8. Reconnect Hoses: Attach the fuel inlet and outlet hoses to the new pump and secure them with the clamps.
9. Final Checks: Reconnect the battery. Prime the fuel system according to your engine's manual. Check carefully for any fuel leaks before starting the engine.

Troubleshooting & FAQ

How do I confirm this fuel pump fits my engine?

First, check the "Compatible Engine Models" tables to see if your model and year range are listed. Second, verify that your existing part number is listed in our "Part Number Cross-Reference" table. For Mercury owners, we provide a Serial Number Guide to help you identify your engine.

What are common signs of a failing fuel pump?

Symptoms of a faulty fuel pump include the engine sputtering (especially at high speeds), loss of power, difficulty starting the engine, or unexpected stalling. If you experience these issues, the fuel pump may be the cause.

Is a gasket included with this pump?

The package contains the fuel pump assembly as shown in the product images. Gaskets or O-rings are often required for a complete seal but are not included with this part. We recommend checking the condition of your old gasket to see if it can be reused or if a new one needs to be purchased separately.

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.