Fuel Pump for Tohatsu, Nissan & Mercury 4–9.8 HP 4-Stroke Outboards – Replaces 3H6-04000-7 and 803529T06
Fuel Pump for Tohatsu, Nissan & Mercury 4–9.8 HP 4-Stroke Outboards – Replaces 3H6-04000-7 and 803529T06 is backordered and will ship as soon as it is back in stock.
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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.
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Fuel Pump for Tohatsu, Nissan & Mercury 4–9.8 HP 4-Stroke Outbo...
Fuel Pump for Tohatsu, Nissan & Mercury 4–9.8 HP 4-Stroke Outboards – Replaces 3H6-04000-7 and 803529T06 is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket fuel pump is intended as a replacement for selected Tohatsu, Nissan, Mercury, and Mariner 4-stroke outboard engines rated from 4 HP to 9.8 HP. It is designed to support reliable fuel delivery for normal engine operation.
The listed replacement references include Tohatsu numbers 3H6-04000-7, 3H6-04000-3, and 3H6-04000-4, along with Mercury references 803529T06 and 803529T01 through 803529T05. Confirm the number on your original pump and compare the pump configuration before ordering.
- Aftermarket replacement fuel pump for selected small 4-stroke outboards.
- Metal housing suitable for typical marine service conditions.
- Package includes an O-ring and hose clamp as listed below.
- Fitment depends on the exact engine model, year, serial range, and original part number.
Part Number Matrix
Use these references as an interchange guide only. Always verify the complete engine identification and compare the original component before installation.
| Brand | Part Number |
|---|---|
| Tohatsu | 3H6-04000-7 |
| Tohatsu | 3H6-04000-3 |
| Tohatsu | 3H6-04000-4 |
| Mercury | 803529T06 |
| Mercury | 803529T01 |
| Mercury | 803529T02 |
| Mercury | 803529T03 |
| Mercury | 803529T04 |
| Mercury | 803529T05 |
Engine & Model Compatibility
This replacement is listed for selected Tohatsu, Nissan, Mercury, and Mariner 4-stroke outboards in the 4 HP to 9.8 HP range. The broad horsepower range alone does not confirm fitment; exact model, year, serial range, stroke, and original pump number must be checked together.
| Brand | Application Scope | Rated HP | Stroke | Year / Serial Condition | Reference Numbers |
|---|---|---|---|---|---|
| Tohatsu | Selected small outboard models | 4–9.8 HP | 4-Stroke | Confirm exact model, year, and serial range | 3H6-04000-7, 3H6-04000-3, 3H6-04000-4 |
| Nissan | Selected small outboard models | 4–6 HP | 4-Stroke | Confirm exact model, year, and serial range | Compare with original pump and reference number |
| Mercury / Mariner | Selected small outboard models | 4–9.8 HP | 4-Stroke | Confirm exact model, year, and serial range | 803529T06 and 803529T01–803529T05 |
Technical Specifications
- Product Type
- Aftermarket fuel pump
- Application
- Selected gasoline 4-stroke outboard engines
- Installation
- Replacement installation; verify fit before purchase
- Housing Material
- Metal, listed as aluminum
- Housing Color
- Silver
- Approximate Package Dimensions
- 10 × 9 × 6 cm
- Approximate Weight
- 176 g (0.39 lb)
What's in the Box
- 1 × Fuel pump
- 1 × Hose clamp, listed as 95395, approximately 9 × 1 mm
- 1 × O-ring, listed as 803513, approximately 2.4 × 20 mm inner diameter
Installation Notes
- Confirm that the replacement pump matches the original pump and the engine's exact model and part-number requirements.
- Allow the engine to cool, disconnect the battery negative terminal, and work in a well-ventilated area away from ignition sources.
- Turn off the fuel supply and safely relieve fuel-system pressure where applicable.
- Place an absorbent cloth beneath the pump to collect spilled fuel.
- Disconnect the fuel inlet and outlet lines, noting their original routing and orientation.
- Remove the mounting fasteners and take off the old pump.
- Clean the mounting surface and inspect the fuel lines, fittings, and clamps for damage or deterioration.
- Install the supplied O-ring and replacement pump. Tighten the mounting fasteners to the engine manufacturer's specification.
- Reconnect the fuel lines securely and install the supplied hose clamp where applicable.
- Restore the fuel supply, reconnect the battery, and prime the fuel system according to the engine service procedure.
- Before operating the engine, inspect the pump and all connections for fuel leaks.
Troubleshooting & FAQ
How do I confirm whether this fuel pump fits my engine?
Check the complete engine brand, model, year, serial range, horsepower, and stroke configuration. Compare the original pump's part number, mounting arrangement, fuel-line connections, and physical configuration with the references listed on this page. A horsepower match by itself is not sufficient.
What are common signs of a failing fuel pump?
Possible symptoms include hard starting, sputtering, hesitation, loss of power, engine stalling, or fuel leakage around the pump or its connections. These symptoms can also result from blocked filters, damaged fuel lines, carburetor problems, or other fuel-system faults.
Is there a fixed replacement interval?
Fuel pumps generally do not have one universal replacement interval. Inspect the pump during routine service and replace it when leakage, damage, deterioration, or fuel-delivery problems are found.
Are special tools required?
Basic hand tools are typically sufficient for removal and installation. A torque wrench is recommended when tightening mounting fasteners to the engine manufacturer's specification.
Is this an OEM part?
No. This listing is for an aftermarket replacement fuel pump. The references shown are manufacturer or interchange numbers used to help identify the intended application; they do not mean this product is manufactured by Tohatsu, Nissan, Mercury, or Mariner.
How quickly will the order ship?
Available shipping methods, delivery estimates, and shipping charges are shown at checkout and may vary by destination and service level.
What is the warranty and return policy?
Warranty coverage and return eligibility are governed by the applicable order and store policies. Contact support with your order details before returning or installing a part if you believe it is incorrect or defective.
Safety & Important Information
- Work only on a cool engine in a well-ventilated area and keep fuel away from flames, sparks, and other ignition sources.
- Verify the exact engine model, year, serial range, stroke, and original part number before ordering.
- Compare the product's dimensions, connections, mounting points, and appearance with the original component.
- Do not operate the engine if fuel leaks are present.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended when the correct fuel-system procedure or torque specifications are unavailable.
About Sea Sierra
- Marine Replacement Parts — Practical replacement components for common marine repair applications.
- Fitment-Focused Listings — Product references and application guidance are provided to help with pre-purchase comparison.
- Customer Support — Contact support if you need help comparing the replacement with your original component.
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