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

Product Details

This replacement fuel pump is designed for a range of 4-stroke Tohatsu and Nissan outboard motors from 4 HP through 9.8 HP, as well as selected 4-stroke Mercury and Mariner 4 HP through 6 HP engines. Confirm the complete engine model, year, stroke type, and existing part number before ordering.

This fuel pump is listed as an aftermarket replacement for Tohatsu references in the 3H6-04000 series and Mercury references including 803529T, 803529T01, 803529T02, 803529T03, and 803529T06. Reference numbers identify possible replacements and should be checked against the application details for your engine.

• Replacement fuel pump assembly for selected small 4-stroke outboards.
• Designed for direct replacement where the listed model and part-number conditions match.
• Metal housing for use in marine fuel-system applications.
• One complete fuel pump assembly is included.

Part Number Matrix

Use the following manufacturer reference numbers to compare with the pump removed from your engine.

Engine & Model Compatibility

The following applications are listed for Tohatsu and Nissan 4-stroke outboards. Mercury and Mariner replacement references are provided above, but specific model and year applications for those brands are not listed here. Match every applicable condition before installation.

Technical Specifications

Product Type

Fuel pump assembly

Application

Selected 4-stroke outboard engines

Fuel Type

Gasoline

Housing Material

Metal

Product Status

Aftermarket replacement, not an OEM component

What's in the Box

• 1 × Fuel pump assembly

Gaskets, mounting hardware, fuel lines, and clamps are not listed as included. Confirm the condition of the existing gasket and replace it when required for a proper seal.

Installation Notes

1. Make sure the engine is switched off and completely cool. Disconnect the battery and relieve fuel-system pressure according to the engine service manual.
2. Place an absorbent rag beneath the pump to catch residual fuel.
3. Disconnect the fuel inlet and outlet lines, noting their original routing and orientation.
4. Remove the fasteners securing the old pump and retain reusable hardware if appropriate.
5. Clean the mounting surface and inspect the gasket and mating surfaces.
6. Install the replacement pump with the correct gasket and tighten the fasteners to the manufacturer's specified torque.
7. Reconnect the fuel lines to the correct ports and secure them with suitable clamps.
8. Prime the fuel system according to the engine manual. Inspect all connections for leaks before starting and again after the engine reaches operating condition.

Troubleshooting & FAQ

Safety & Important Information

• Fuel is flammable. Work in a well-ventilated area away from sparks, flames, hot surfaces, and other ignition sources.
• Verify the pump configuration and reference number against the original component and the engine service information before purchase.
• Do not operate the engine if any fuel connection leaks.
• This is an aftermarket replacement, not an OEM component.
• Professional installation is recommended when fuel-system service procedures or engine-specific torque requirements are unfamiliar.

About Sea Sierra

• Marine Replacement Parts — Replacement components for a range of marine repair applications.
• Application-Focused Listings — Product references and compatibility details are provided to help you compare the part with your engine.
• Support for Part Identification — Compare the complete engine and component details before ordering.