Fuel Pump – Fits Mercury 4–6 HP & Tohatsu/Nissan 4–9.8 HP 4-Stroke Outboards (Replaces 803529T06, 3H6-04000)
Fuel Pump – Fits Mercury 4–6 HP & Tohatsu/Nissan 4–9.8 HP 4-Stroke Outboards (Replaces 803529T06, 3H6-04000) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Fuel Pump – Fits Mercury 4–6 HP & Tohatsu/Nissan 4–9.8 HP 4-Str...
Product Details
This Fuel Pump – Fits Mercury 4–6 HP & Tohatsu/Nissan 4–9.8 HP 4-Stroke Outboards is a direct-fit replacement for various Mercury/Mariner (4-6 HP) and Tohatsu/Nissan (4-9.8 HP) 4-stroke outboard models, covering multiple model years from 2002 to 2014 and beyond.
It serves as a direct interchange for Mercury part number 803529T06 and Tohatsu/Nissan 3H6-04000, among other superseded numbers. This ensures broad compatibility for routine maintenance or repair.
- Engineered for direct-replacement installation.
- Durable metal housing for reliable performance in marine environments.
- Includes one complete fuel pump assembly.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| 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 & Model Compatibility
Confirm your engine model/year in the table below.
For Mercury/Mariner models, verify compatibility against your engine's serial number range as listed in the notes.
| Brand | Model | Rated HP | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|---|
| Mercury | F4 | 4 | 4-Stroke | 803529T06 | Serial ranges: 0P401000-0R411837, 0R067090-0R411837, 0R411838 & Up, 0P073456-0P400999, 0R000001-0R067089 |
| Mercury | F5 | 5 | 4-Stroke | 803529T06 | Serial ranges: 0P401000-0R411837, 0R067090-0R411837, 0R411838 & Up, 0P073456-0P400999, 0R000001-0R067089 |
| Mercury | F5 (International) | 5 | 4-Stroke | 803529T06 | Serial range: 0R560794 & Up |
| Mercury | F6 | 6 | 4-Stroke | 803529T06 | Serial ranges: 0P401000-0R411837, 0R067090-0R411837, 0R411838 & Up, 0P073456-0P400999, 0R000001-0R067089 |
Compatibility for Tohatsu and Nissan models is listed below by model and year.
| Brand | Model | Rated HP | Stroke | Years | OEM 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 Specs
- Product Type
- Outboard Fuel Pump
- Installation
- Direct replacement
- Fuel Type
- Gasoline
- Connection
- Hose Barb
- Housing Material
- Metal
- Housing Color
- Silver
- Weight
- 5.9 ounces (167g)
- Fitting Type
- Vehicle Specific Fit
- Other Technical Attributes
- Medium Weight Class
What’s in the Box
- 1 x Fuel Pump (803529T06/3H6-04000)
Installation Notes
- Disconnect the engine's battery cables to prevent accidental starting.
- Safely relieve any pressure from the fuel system. Place a rag around fittings to catch fuel spillage.
- Carefully disconnect the fuel inlet and outlet hoses from the old pump. Note their orientation.
- Unbolt and remove the old fuel pump from the engine block.
- Mount the new fuel pump securely in the same position.
- Reconnect the fuel hoses to the correct ports on the new pump and secure the clamps.
- Reconnect the battery, prime the fuel system if necessary, and inspect for any leaks before starting the engine.
Troubleshooting & FAQ
How do I confirm this pump fits my specific engine?
The best way is to match your old part number to one listed in the Part Number Matrix. If you can't find the part number, check the Engine & Model Compatibility tables. Pay close attention to serial number ranges for Mercury models, as fitment can be specific.
What are the common signs of a failing outboard fuel pump?
Symptoms include difficulty starting the engine, engine sputtering or stalling (especially at high speeds), loss of power, and inconsistent fuel flow. A physical inspection might reveal cracks or leaks in the pump housing.
Is this a low-pressure or high-pressure pump?
This is a low-pressure mechanical lift pump, designed to transfer fuel from the tank to the carburetors. It is not intended for fuel-injected (EFI) systems which require a high-pressure electric pump.
How often should this fuel pump be replaced?
There is no fixed replacement interval. It should be inspected periodically for signs of wear, leakage, or reduced performance and replaced when it no longer functions correctly. Factors like fuel quality and ethanol content can affect its lifespan.
Can I install this part myself?
While installation is straightforward for those with mechanical experience, we recommend professional installation to ensure safety and proper function. Incorrect installation can lead to fuel leaks, which are a serious fire hazard.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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