Fuel Pump Diaphragm – Fits Yamaha 25-30HP 3-Cylinder Outboard (Replaces 6J8-24471-00-00)
Fuel Pump Diaphragm – Fits Yamaha 25-30HP 3-Cylinder Outboard (Replaces 6J8-24471-00-00) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
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Delivery and Shipping
Free standard shipping on all orders under 1 KG
Fuel Pump Diaphragm – Fits Yamaha 25-30HP 3-Cylinder Outboard (Repl...
Product Details
This Fuel Pump Diaphragm – Fits Yamaha 25-30HP 3-Cylinder Outboard (Replaces 6J8-24471-00-00) is designed as a direct-fit component for Yamaha's 25HP and 30HP 3-cylinder, 2-stroke outboard motors manufactured from 1984 to 2002. It restores proper fuel delivery by replacing a worn or damaged diaphragm in the mechanical fuel pump assembly.
This part offers a direct interchange for Yamaha 6J8-24471-00-00, Mercury 804011, and Sierra 18-7841, ensuring broad compatibility for repairs and maintenance.
- Installs as a direct OEM-style replacement.
- Made from durable, gasoline-resistant synthetic rubber materials.
- Essential component for rebuilding mechanical fuel pump assemblies.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 6J8-24471-00-00 |
| Mercury | 804011 |
| Sierra | 18-7841 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This diaphragm fits select Yamaha 3-cylinder outboard models. Verify your engine's part number requirements before ordering.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | 25HP 3-Cylinder | 25 | 2-Stroke | 1987–2002 | 6J8-24471-00-00 | |
| Yamaha | 30HP 3-Cylinder | 30 | 2-Stroke | 1987–2002 | 6J8-24471-00-00 |
Technical Specs
- Product Type
- Fuel Pump Diaphragm
- Installation
- Direct OEM replacement
- Fuel Type
- Gasoline
- Housing Material
- Rubber/Synthetic
- Dimensions
- 1.13″ L x 4.0″ W x 5.13″ H
- Weight
- 10g (0.35 oz)
- Warranty
- 30 day (Crowley Marine)
- Other Technical Attributes
- For mechanical fuel pump assembly
What’s in the Box
- 1 x Diaphragm (6J8-24471-00-00)
Installation Notes
- Disconnect the negative battery terminal and relieve fuel system pressure.
- Carefully disconnect the fuel inlet and outlet lines from the fuel pump.
- Remove the mounting bolts securing the fuel pump assembly to the engine block.
- Disassemble the pump housing, taking care to note the orientation of the cover, diaphragm, and spring.
- Remove the old diaphragm and clean the housing surfaces of any debris or gasket material.
- Install the new diaphragm, ensuring it is correctly aligned with any locating tabs or holes.
- Reassemble the fuel pump, tighten the screws evenly, and mount it back onto the engine.
- Reconnect the fuel lines securely.
- Prime the fuel system using the primer bulb until firm, and inspect carefully for any leaks before starting the engine.
Troubleshooting & FAQ
How do I know if my fuel pump diaphragm is failing?
Common signs of a failed diaphragm include the engine having difficulty starting, bogging down at high speeds, stalling, rough idling, or visible fuel leaks from the pump itself. A physical inspection may reveal cracks, stiffness, or tears in the diaphragm material.
Does this diaphragm fit all 25-30HP Yamaha models?
No. This part specifically fits the 3-cylinder, 2-stroke Yamaha 25HP and 30HP models that use the mechanical fuel pump associated with OEM part number 6J8-24471-00-00. Always verify your engine's model and part number before purchasing.
What is the recommended replacement interval for this part?
There is no strict service interval, but fuel pump diaphragms degrade over time from exposure to ethanol and other fuel additives. It is good practice to inspect it during annual service and consider a preventative replacement every 5-7 years, or immediately if it appears stiff, brittle, or deformed.
Is this a complete fuel pump kit?
No, this listing is for the replacement diaphragm only. It does not include the fuel pump housing, gaskets, or other hardware. It is intended for rebuilding your existing fuel pump assembly.
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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