Fuel Filter Kit – Fits MerCruiser 2.5L, 3.0L, 3.7L, 4.3L Sterndrive Engines (Replaces 35-803897Q1, 8M0046752)
Fuel Filter Kit – Fits MerCruiser 2.5L, 3.0L, 3.7L, 4.3L Sterndrive Engines (Replaces 35-803897Q1, 8M0046752) 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.).
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Fuel Filter Kit – Fits MerCruiser 2.5L, 3.0L, 3.7L, 4.3L Sterndrive...
Product Details
This Fuel Filter Kit – Fits MerCruiser 2.5L, 3.0L, 3.7L, 4.3L Sterndrive Engines is an essential service part for maintaining engine health and efficiency. It is designed for a range of MerCruiser 2.5L, 3.0L, 3.7L, and 4.3L 4-stroke sterndrive engines, covering specific models manufactured from the 1980s through the 2000s that use a mechanical fuel pump with an internal filter.
The kit serves as a direct interchange for MerCruiser part numbers 35-803897Q1, 8M0046752, 35-11004A1, 35-11004Q2, 35-803897, 803897Q1, and 803897K1, along with several other aftermarket equivalents.
- Installs inside the lower canister of the mechanical fuel pump mounted on the engine block.
- Designed for use with gasoline-fueled inboard and sterndrive engines.
- Includes the filter element, spring, and all necessary rubber gaskets and rings for a complete replacement.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| MerCruiser | 35-803897Q1 / 8M0046752 |
| MerCruiser | 35-11004A1 / 35-11004Q2 / 35-803897 |
| MerCruiser | 803897Q1 / 803897K1 |
| Sierra | 18-7784 |
| Mallory | 9-37821 |
| Volvo Penta | 3855104 |
| GLM | 24850 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For MerCruiser models, compatibility often depends on the serial number (s/n) and the type of fuel pump installed. This filter is for models equipped with a mechanical fuel pump that houses the filter internally.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | 2.5L | 120 | 4-Stroke | 1980s–1990s (s/n 6229718 & Later) | 35-803897Q1 | Requires filter mounted in mechanical fuel pump |
| MerCruiser | 3.0L | 140/LX | 4-Stroke | 1980s–2000s (s/n 6229718 & Later) | 35-803897Q1 | Requires filter mounted in mechanical fuel pump |
| MerCruiser | 3.7L | 165, 170, 180, 190 CI | 4-Stroke | s/n 6916779 & Later | 35-803897Q1 | Requires filter mounted in mechanical fuel pump |
| MerCruiser | MC224 | - | 4-Stroke | s/n 6218037 & Later | 35-803897Q1 | All MC224 C.I. engines |
| MerCruiser | GM 262 C.I. (4.3L) | - | 4-Stroke | s/n 0A331455 & Later | 35-803897Q1 | Only models with Carter Fuel Pumps |
| MerCruiser | Alpha 1 | - | 4-Stroke | - | 35-803897Q1 | With compatible engine configurations |
Technical Specs
- Product Type
- Mechanical Fuel Pump Filter Kit
- Installation
- Located within the lower canister of the mechanical fuel pump mounted on the engine
- Fuel Type
- Gasoline
- Connection
- Internal filter element in mechanical fuel pump
- Fitting Type
- Internal filter
- Warranty
- 1 year (varies by retailer)
- Other Technical Attributes
- Complete kit includes filter element, spring, and rubber gaskets/rings
What’s in the Box
- 1 x Filter Element
- 1 x Spring
- 3 x Rubber Rings/Gaskets
Installation Notes
- Ensure the engine is cool and disconnect the battery's negative terminal for safety.
- Relieve fuel system pressure according to your engine's service manual procedures. Place rags or absorbent pads under the fuel pump to catch any spilled gasoline.
- Locate the mechanical fuel pump on the side of the engine block. Identify and carefully unscrew the lower canister housing the filter.
- Remove the old filter, spring, and rubber gaskets. Note their orientation before removal.
- Clean the inside of the canister and inspect it for any debris or damage.
- Install the new gasket, spring, and filter element in the reverse order of removal.
- Securely tighten the pump canister. Do not overtighten.
- Reconnect the battery. Prime the fuel system as per the manufacturer's instructions, check for any leaks, and start the engine to confirm proper operation.
Troubleshooting & FAQ
How do I find my engine's serial number to confirm fitment?
The serial number is typically found on a metal plate or sticker on the engine block, cylinder head, or flame arrestor cover. The exact location varies by model and year.
What are the signs of a clogged fuel filter?
Common symptoms include engine hesitation or stumbling under acceleration, difficulty starting, rough idling, reduced top-end power, and stalling. These issues occur because the engine isn't receiving enough fuel.
What is the recommended replacement interval for this filter?
For optimal performance and to prevent fuel system issues, it's recommended to replace this filter annually or every 100 hours of operation, whichever comes first. Refer to your engine's service manual for specific guidance.
Is this filter compatible with all 4.3L MerCruiser engines?
No. It only fits specific 4.3L models (s/n 0A331455 & later) that are equipped with Carter-brand mechanical fuel pumps. It will not fit models with other fuel pump types (e.g., electric fuel pumps).
Why does the kit include multiple gaskets?
The kit includes different gaskets to fit the variations in fuel pump designs across the wide range of compatible engine years and models. Use the gasket that matches your original part to ensure a proper seal.
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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