Fuel Pump – Fits Mercury 4–6 HP and Tohatsu/Nissan 4–9.8 HP 4-Stroke Outboards (Replaces 803529T06 and 3H6-04000)
Fuel Pump – Fits Mercury 4–6 HP and Tohatsu/Nissan 4–9.8 HP 4-Stroke Outboards (Replaces 803529T06 and 3H6-04000) is backordered and will ship as soon as it is back in stock.
Worry-free returns
Worry-free returns
Shop with confidence. If you’re not completely satisfied, eligible items may be returned within the return window, provided they are unused and in original packaging.
If the return is due to our error or a defective item, we’ll make it right.
Please contact us before returning any item.
Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
U.S. orders usually arrive within 6–15 days, depending on stock location and destination.
International delivery times may vary due to customs processing.
Tracking information will be provided once your order ships.
Fuel Pump – Fits Mercury 4–6 HP and Tohatsu/Nissan 4–9.8 HP 4-Strok...
Fuel Pump – Fits Mercury 4–6 HP and Tohatsu/Nissan 4–9.8 HP 4-Stroke Outboards (Replaces 803529T06 and 3H6-04000) is backordered and will ship as soon as it is back in stock.
Product Details
This outboard fuel pump is a replacement for selected Mercury and Mariner 4–6 HP 4-stroke outboards and Tohatsu/Nissan 4–9.8 HP 4-stroke outboards. The listed applications cover multiple model years and should be checked against the engine model, year, and serial-number conditions shown below.
This pump is listed as an aftermarket replacement for Mercury part number 803529T06 and Tohatsu/Nissan part number 3H6-04000, along with the related reference numbers in the matrix. Confirm the original pump and application before ordering.
- Designed as a direct-replacement fuel pump for the listed outboard applications.
- Metal housing for use in marine fuel-system applications.
- Supplied as one complete fuel pump assembly.
Part Number Matrix
Use the following manufacturer and reference numbers to compare the replacement with the pump being removed.
| Brand | Part Number |
|---|---|
| Mercury | 803529T06 |
| Mercury | 803529T03 |
| Mercury | 803529T02 |
| Mercury | 803529T1 |
| Mercury | 803529T |
| Tohatsu/Nissan | 3H6-04000-1 |
| Tohatsu/Nissan | 3H6-04000-3 |
| Tohatsu/Nissan | 3H6-04000-4 |
| Tohatsu/Nissan | 3H6040000M |
| Tohatsu/Nissan | 3H6040001M |
| Tohatsu/Nissan | 3H6040002M |
| Tohatsu/Nissan | 3H6040003M |
| Tohatsu/Nissan | 3H6040004M |
| Tohatsu/Nissan | 3H6040007M |
Engine and Model Compatibility
Compatibility depends on the exact model, year, and serial-number range. Match all available information before installation.
Mercury and Mariner 4-Stroke Applications
| Brand | Model | Rated HP | Stroke | Reference Part No. | Serial-Number Conditions |
|---|---|---|---|---|---|
| Mercury | F4 | 4 | 4-Stroke | 803529T06 | 0P401000–0R411837; 0R067090–0R411837; 0R411838 and up; 0P073456–0P400999; 0R000001–0R067089 |
| Mercury | F5 | 5 | 4-Stroke | 803529T06 | 0P401000–0R411837; 0R067090–0R411837; 0R411838 and up; 0P073456–0P400999; 0R000001–0R067089 |
| Mercury | F5 International | 5 | 4-Stroke | 803529T06 | 0R560794 and up |
| Mercury | F6 | 6 | 4-Stroke | 803529T06 | 0P401000–0R411837; 0R067090–0R411837; 0R411838 and up; 0P073456–0P400999; 0R000001–0R067089 |
Tohatsu and Nissan 4-Stroke Applications
| Brand | Model | Rated HP | Stroke | Years | Reference Part No. |
|---|---|---|---|---|---|
| Tohatsu | MFS4C | 4 | 4-Stroke | 2011–2014 | 3H6-04000 |
| Nissan | NSF4C | 4 | 4-Stroke | 2011–2014 | 3H6-04000 |
| Tohatsu | MFS4B | 4 | 4-Stroke | 2005–2010 | 3H6-04000 |
| Nissan | NSF4B | 4 | 4-Stroke | 2005–2010 | 3H6-04000 |
| Tohatsu | MFS4A2 | 4 | 4-Stroke | 2002 | 3H6-04000 |
| Nissan | NSF4A2 | 4 | 4-Stroke | 2002 | 3H6-04000 |
| Tohatsu | MFS5C | 5 | 4-Stroke | 2011–2014 | 3H6-04000 |
| Nissan | NSF5C | 5 | 4-Stroke | 2011–2014 | 3H6-04000 |
| Tohatsu | MFS5B | 5 | 4-Stroke | 2005–2010 | 3H6-04000 |
| Nissan | NSF5B | 5 | 4-Stroke | 2005–2010 | 3H6-04000 |
| Tohatsu | MFS5A2 | 5 | 4-Stroke | 2002 | 3H6-04000 |
| Nissan | NSF5A2 | 5 | 4-Stroke | 2002 | 3H6-04000 |
| Tohatsu | MFS6C | 6 | 4-Stroke | 2011–2014 | 3H6-04000 |
| Nissan | NSF6C | 6 | 4-Stroke | 2011–2014 | 3H6-04000 |
| Tohatsu | MFS6B | 6 | 4-Stroke | 2005–2010 | 3H6-04000 |
| Nissan | NSF6B | 6 | 4-Stroke | 2005–2010 | 3H6-04000 |
| Tohatsu | MFS6A2 | 6 | 4-Stroke | 2002 | 3H6-04000 |
| Nissan | NSF6A2 | 6 | 4-Stroke | 2002 | 3H6-04000 |
| Tohatsu | MFS8A3 | 8 | 4-Stroke | 2006, 2009–2014 | 3H6-04000 |
| Nissan | NSF8A3 | 8 | 4-Stroke | 2006, 2009–2014 | 3H6-04000 |
| Tohatsu | MFS8A2 | 8 | 4-Stroke | 2004 | 3H6-04000 |
| Nissan | NSF8A2 | 8 | 4-Stroke | 2004 | 3H6-04000 |
| Tohatsu | MFS9.8A3 | 9.8 | 4-Stroke | 2006, 2009–2014 | 3H6-04000 |
| Nissan | NSF9.8A3 | 9.8 | 4-Stroke | 2006, 2009–2014 | 3H6-04000 |
| Tohatsu | MFS9.8A2 | 9.8 | 4-Stroke | 2004 | 3H6-04000 |
| Nissan | NSF9.8A2 | 9.8 | 4-Stroke | 2004 | 3H6-04000 |
Technical Specifications
- Product Type
- Outboard fuel pump
- Installation
- Direct replacement
- Fuel Type
- Gasoline
- Connection
- Hose barb
- Housing Material
- Metal
- Housing Color
- Silver
- Weight
- 5.9 ounces (167 g)
- Fitting Type
- Vehicle-specific fit
- Other Technical Attribute
- Medium weight class
What's in the Box
- 1 × fuel pump assembly
Installation Notes
- Disconnect the engine battery cables to help prevent accidental starting.
- Relieve fuel-system pressure safely. Place an absorbent rag around the fittings to catch fuel spillage.
- Disconnect the fuel inlet and outlet hoses from the old pump, and note their orientation.
- Remove the fasteners securing the old pump to the engine.
- Install the replacement pump in the same position and secure it properly.
- Reconnect the fuel hoses to the correct ports and secure the hose clamps.
- Reconnect the battery, prime the fuel system if required, and inspect all connections for leaks before starting the engine.
Troubleshooting and FAQ
How do I confirm that this pump fits my engine?
Compare the part number on your original pump with the numbers in the Part Number Matrix. If the original number is unavailable, match the engine brand, model, horsepower, stroke, year, and—where applicable—the Mercury serial-number range in the compatibility tables. Do not rely on horsepower alone.
What are common signs of a failing outboard fuel pump?
Possible symptoms include difficult starting, sputtering or stalling, loss of power, inconsistent fuel delivery, and visible cracking or leakage around the pump. Test the fuel system according to the engine manufacturer's service procedures before replacing parts.
Is this a low-pressure or high-pressure pump?
This listing describes a low-pressure mechanical lift pump for transferring fuel from the tank to the engine's fuel system. It is not intended to replace a high-pressure electric pump used by a fuel-injected system.
How often should the fuel pump be replaced?
There is no universal replacement interval. Inspect the pump during routine maintenance and replace it if it leaks, is damaged, or no longer delivers fuel correctly. Fuel quality and operating conditions can affect service life.
Can I install this part myself?
Installation may be straightforward for an experienced mechanic, but fuel-system work presents a fire hazard. Use proper ventilation, keep the engine away from ignition sources, and seek professional service if you are not familiar with outboard fuel systems.
Is this an OEM part?
This is an aftermarket replacement, not an OEM-branded component. Compare the original pump, fittings, mounting arrangement, and applicable part number before purchase.
How do I verify compatibility before ordering?
Confirm the original part number and all applicable engine conditions. For Mercury applications, pay particular attention to the serial-number range. For Tohatsu and Nissan applications, verify the exact model and model year.
Safety and Important Information
- Verify the original part number, appearance, fittings, mounting arrangement, and engine application before ordering.
- Compatibility must be confirmed using the complete model, year, horsepower, stroke, and serial-number information where applicable.
- This is an aftermarket replacement, not an OEM component.
- Fuel leaks can create a fire hazard. Inspect every connection carefully after installation.
- Professional installation is recommended when you are uncertain about fuel-system service.
About Sea Sierra
- Pro-Grade Standards — We supply marine replacement parts selected for practical service and real-world operating conditions.
- Global Fulfillment — Delivery options and estimated transit times are shown at checkout according to destination and service selected.
- Manufacturer-Direct Value — We aim to provide dependable replacement parts at competitive prices.
Payment & Security
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
