Inline Fuel Filter – Fits Yamaha 4-9.9 HP (Replaces 646-24251-01-00, 646-24251-02-00)
Inline Fuel Filter – Fits Yamaha 4-9.9 HP (Replaces 646-24251-01-00, 646-24251-02-00) 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
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Inline Fuel Filter – Fits Yamaha 4-9.9 HP (Replaces 646-24251-01-00...
Product Details
This replacement Inline Fuel Filter – Fits Yamaha 4-9.9 HP Outboards is designed to protect your engine’s fuel system from contaminants. It fits a range of Yamaha 2-stroke (1989–2002) and 4-stroke (F4A, F8A, F8B, F9.9A/FT9.9A) models. It is also used on remote oil tanks for all Yamaha 2-Stroke and HPDI models, and fits specific Mercury 9.9 HP 2-stroke outboards (1995–1998).
This part is a direct replacement for Yamaha 646-24251-01-00 and 646-24251-02-00, Mercury 35-80365M, Sierra 18-7713, and Mallory 9-37969.
- Installs inline under the engine cowl.
- Translucent housing for visual inspection of fuel flow and contaminants.
- Directional flow arrow ensures correct installation toward the fuel pump.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Yamaha | 646-24251-02-00 | Current Part |
| Yamaha | 646-24251-01-00 | Superseded part |
| Yamaha | 646-24251-00 | Superseded part |
| Mercury | 35-80365M | |
| Sierra | 18-7713 | |
| Mallory | 9-37969 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Yamaha engines, this filter fits a variety of small-horsepower 2-stroke and 4-stroke models. It is also found on the remote oil tanks of all 2-stroke and HPDI outboards.
For Mercury engines, this filter is applicable to 9.9 HP 2-stroke models from 1995–1998.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | 4A, 4B | 4 | 2-Stroke | 1989–1999 | 646-24251-01-00/646-24251-02-00 | |
| Yamaha | 5C | 5 | 2-Stroke | 1997–2002 | 646-24251-01-00/646-24251-02-00 | |
| Yamaha | 6C, 6D | 6 | 2-Stroke | 1986–2000 | 646-24251-01-00/646-24251-02-00 | |
| Yamaha | 8C | 8 | 2-Stroke | 1989–2001 | 646-24251-01-00/646-24251-02-00 | |
| Yamaha | F4A | 4 | 4-Stroke | 1999–2008 | 646-24251-01-00/646-24251-02-00 | |
| Yamaha | F8A, F8B | 8 | 4-Stroke | 1999–2002 | 646-24251-01-00/646-24251-02-00 | |
| Yamaha | F9.9A, F9.9BA | 9.9 | 4-Stroke | 1989–2002 | 646-24251-01-00/646-24251-02-00 | |
| Yamaha | FT9.9A | 9.9 | 4-Stroke | 1988–1990 | 646-24251-01-00/646-24251-02-00 | High thrust model |
| Yamaha | All Two-Stroke Models | Various | 2-Stroke | Various | 646-24251-01-00/646-24251-02-00 | Used on remote oil tanks |
| Yamaha | HPDI Models | Various | 2-Stroke | Various | 646-24251-01-00/646-24251-02-00 | Used on remote oil tanks |
| Mercury | 9.9 | 9.9 | 2-Stroke | 1995–1998 | 35-80365M |
Technical Specs
- Product Type
- Inline Fuel Filter
- Installation
- Inline (under cowl)
- Fuel Type
- Gasoline (including ethanol blends)
- Connection
- Inline fuel line connection
- Housing Material
- Marine-grade plastic
- Housing Color
- Translucent
- Fitting Type
- Barbed hose connectors
- Thread Size
- N/A (press-fit)
- Flow Direction
- Directional (arrow must point toward fuel pump)
- Warranty
- Varies by manufacturer
What’s in the Box
- 1 x Inline Fuel Filter (646-24251-01-00/646-24251-02-00)
Installation Notes
- Ensure the engine is off and the battery is disconnected.
- Work in a well-ventilated area and have a fire extinguisher nearby.
- Locate the existing fuel filter under the engine cowl. Note the direction of the flow arrow on the old filter.
- Place a rag under the filter to catch any spilled fuel. Release any pressure in the fuel line carefully.
- Disconnect the fuel lines from the old filter, typically held by clamps.
- Install the new filter, ensuring the flow arrow points toward the engine's fuel pump.
- Secure the fuel lines onto the new filter with the clamps.
- Prime the fuel system if necessary. Once reconnected, check thoroughly for any leaks before starting the engine.
Troubleshooting & FAQ
How do I know if this filter fits my engine?
The most reliable method is to match the part number from your old filter to one of the numbers listed in our Part Number Matrix. You can also check your engine model and year against our compatibility table. When in doubt, visually compare your existing filter to our product images.
What is the correct installation orientation?
The filter is directional. There is an arrow on the housing that must point in the direction of fuel flow—away from the fuel tank and toward the fuel pump on the engine.
When should this fuel filter be replaced?
As a general guideline, replace your inline fuel filter annually or every 100 hours of operation, whichever comes first. Refer to your engine’s service manual for the manufacturer’s recommended interval.
What are signs of a clogged fuel filter?
Common symptoms include engine sputtering, loss of power, difficulty starting, or stalling, especially under load. You may also see debris inside the translucent housing.
What is the difference between OEM and aftermarket parts?
This listing is for an aftermarket replacement, not an original equipment manufacturer (OEM) part. It is built to meet or exceed OEM-level specifications using comparable materials and is manufactured in an ISO 9002 facility. All parts are batch-inspected for quality and consistency.
What are your shipping speeds and costs?
We ship worldwide quickly, with typical transit times of 5–15 days for most regions. Standard shipping is free. If available for your location, expedited shipping options and their costs will be presented at checkout.
What is your warranty and return policy?
This product is covered by a 1-year warranty against manufacturing defects under normal marine use. If you encounter an issue, please contact our support team with your order details. Returns are accepted within our standard window for items that are unused and in their original packaging. Please see our full policy page or reach out for instructions.
Safety & Important Info
- Verify images and specifications against 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.
Payment & Security
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