Fuel Pump Assembly – Fits Tohatsu/Nissan 4-9.8 HP & Mercury/Mariner 4-6 HP 4-Stroke (Replaces 3H6-04000-7, 803529T06)
This fuel pump assembly is designed for a precise fit on a range of Tohatsu, Nissan, Mercury, and Mariner 4-stroke outboard motors. It fits Tohatsu/Nissan models from 4 HP to 9.8 HP and Mercury/Mariner models from 4 HP to 6 HP, ensuring reliable fuel delivery for optimal engine performance.
As a direct replacement, this assembly supersedes multiple Tohatsu and Mercury part numbers, including Tohatsu 3H6-04000-7 and Mercury 803529T06. It provides a straightforward solution for replacing old, worn, or malfunctioning fuel pumps.
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Installation: Installs as a direct OEM-style replacement.
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Fuel Compatibility: Designed for use with Gasoline.
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Housing: Constructed from a durable alloy for corrosion resistance.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across brands. This part is a direct replacement for the following OEM numbers.
| Brand |
Part Number |
Superseded By |
| Tohatsu |
3H6-04000-0 |
3H6-04000-7 |
| Tohatsu |
3H6-04000-1 |
3H6-04000-7 |
| Tohatsu |
3H6-04000-2 |
3H6-04000-7 |
| Tohatsu |
3H6-04000-3 |
3H6-04000-7 |
| Tohatsu |
3H6-04000-4 |
3H6-04000-7 |
| Tohatsu |
3H6-04000-5 |
3H6-04000-7 |
| Tohatsu |
3H6-04000-6 |
3H6-04000-7 |
| Mercury |
803529T1 |
803529T06 |
| Mercury |
803529T02 |
803529T06 |
| Mercury |
803529T03 |
803529T06 |
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.
| Brand |
Model |
Rated HP |
Stroke |
OEM Part No. |
Notes |
| Tohatsu |
MFS4A2 |
4 |
4-Stroke |
3H6-04000-7 |
Supersedes earlier -0 through -6 versions |
| Tohatsu |
MFS4B |
4 |
4-Stroke |
3H6-04000-7 |
Supersedes earlier -0 through -6 versions |
| Tohatsu |
MFS5A2 |
5 |
4-Stroke |
3H6-04000-7 |
Supersedes earlier -0 through -6 versions |
| Tohatsu |
MFS5B |
5 |
4-Stroke |
3H6-04000-7 |
Supersedes earlier -0 through -6 versions |
| Tohatsu |
MFS6A2 |
6 |
4-Stroke |
3H6-04000-7 |
Supersedes earlier -0 through -6 versions |
| Tohatsu |
MFS6B |
6 |
4-Stroke |
3H6-04000-7 |
Supersedes earlier -0 through -6 versions |
| Tohatsu |
MFS8A |
8 |
4-Stroke |
3H6-04000-7 |
Supersedes earlier -0 through -6 versions |
| Tohatsu |
MFS8A2 |
8 |
4-Stroke |
3H6-04000-7 |
Supersedes earlier -0 through -6 versions |
| Tohatsu |
MFS8A3 |
8 |
4-Stroke |
3H6-04000-7 |
Supersedes earlier -0 through -6 versions |
| Tohatsu |
MFS9.8A |
9.8 |
4-Stroke |
3H6-04000-7 |
Supersedes earlier -0 through -6 versions |
| Tohatsu |
MFS9.8A2 |
9.8 |
4-Stroke |
3H6-04000-7 |
Supersedes earlier -0 through -6 versions |
| Tohatsu |
MFS9.8A3 |
9.8 |
4-Stroke |
3H6-04000-7 |
Supersedes earlier -0 through -6 versions |
| Nissan |
NSF4A2 |
4 |
4-Stroke |
3H6-04000-7 |
Supersedes earlier -0 through -6 versions |
| Nissan |
NSF5A2 |
5 |
4-Stroke |
3H6-04000-7 |
Supersedes earlier -0 through -6 versions |
| Nissan |
NSF6A2 |
6 |
4-Stroke |
3H6-04000-7 |
Supersedes earlier -0 through -6 versions |
| Nissan |
NSF8A |
8 |
4-Stroke |
3H6-04000-7 |
Supersedes earlier -0 through -6 versions |
| Nissan |
NSF9.8A |
9.8 |
4-Stroke |
3H6-04000-7 |
Supersedes earlier -0 through -6 versions |
| Brand |
Rated HP |
Stroke |
OEM Part No. |
Notes |
| Mercury |
4 |
4-Stroke |
803529T06 |
Also replaces 803529T1, 803529T02, 803529T03 |
| Mercury |
5 |
4-Stroke |
803529T06 |
Also replaces 803529T1, 803529T02, 803529T03 |
| Mercury |
6 |
4-Stroke |
803529T06 |
Also replaces 803529T1, 803529T02, 803529T03 |
| Mariner |
4 |
4-Stroke |
803529T06 |
Also replaces 803529T1, 803529T02, 803529T03 |
| Mariner |
5 |
4-Stroke |
803529T06 |
Also replaces 803529T1, 803529T02, 803529T03 |
| Mariner |
6 |
4-Stroke |
803529T06 |
Also replaces 803529T1, 803529T02, 803529T03 |
Technical Specifications
| Specification |
Value |
| Product Type |
Fuel Pump Assembly |
| Installation |
Direct OEM Replacement |
| Fuel Type |
Gasoline |
| Connection |
Two hose barbs (inlet/outlet) |
| Housing Material |
Alloy |
| Housing Color |
Silver/Metallic with black top |
| Fitting Type |
Hose barb connections |
| Warranty |
Varies by retailer (typically 1-year against manufacturing defects) |
| Other Technical Attributes |
Production Standard: ISO9002 certified factory |
Package Contents
- 1 x Fuel Pump Assembly (Replaces 3H6-04000-7 / 803529T06)
Installation Guide
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Safety First: Disconnect the battery and ensure the engine is cool. Work in a well-ventilated area away from sparks or open flames.
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Locate Fuel Pump: Identify the existing fuel pump on the engine block.
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Prevent Spills: Place a rag or container under the fuel pump and clamp the fuel lines on both sides to minimize fuel leakage.
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Disconnect Lines: Carefully disconnect the inlet and outlet fuel hoses from the pump. Note their orientation.
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Remove Old Pump: Unbolt the mounting hardware securing the old pump and remove it from the engine.
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Verify Fitment: Before installing, compare the new pump with your old one to ensure the fittings and mounting points match perfectly.
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Install New Pump: Mount the new fuel pump onto the engine and tighten the bolts to the manufacturer's recommended torque.
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Reconnect Lines: Attach the fuel inlet and outlet hoses to the correct ports on the new pump and secure the clamps.
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Final Checks: Remove the clamps from the fuel lines. Reconnect the battery.
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Prime and Test: Prime the fuel system according to your engine's manual. Start the engine and carefully inspect the pump and connections for any leaks.
Troubleshooting & FAQ
- How do I confirm this fits my engine?
- The best way is to match your original part number to the numbers in our Part Number Cross-Reference table. You can also check your engine model against the compatibility lists. If you're still unsure, inspect the product photos to visually match them with your existing part.
- My original part number is 3H6-04000-3. Will this part work?
- Yes. This fuel pump, 3H6-04000-7, is the direct supersession for all previous versions from 3H6-04000-0 through 3H6-04000-6. It will fit and function correctly.
- What are the common signs of a failing fuel pump?
- Symptoms of a bad fuel pump include difficulty starting the engine, stalling at low speeds, rough idling, engine sputtering at high speeds, or a noticeable loss of power. A visual inspection may also reveal cracks or fuel leaks on the pump housing.
- 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?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.