Fuel Filter Kit – Fits MerCruiser 2.5L, 3.0L, 3.7L, 4.3L (Replaces 803897Q1, 8M0046752)
Fuel Filter Kit – Fits MerCruiser 2.5L, 3.0L, 3.7L, 4.3L (Replaces 803897Q1, 8M0046752) 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
Fuel Filter Kit – Fits MerCruiser 2.5L, 3.0L, 3.7L, 4.3L (Replaces ...
Product Details
This Fuel Filter Kit is designed for specific MerCruiser 2.5L, 3.0L, 3.7L, and 4.3L 4-stroke sterndrive engines manufactured from the 1980s to the 2000s. It is compatible with models that utilize a mechanical fuel pump mounted on the engine block, where the filter is housed in the pump's lower canister.
The kit serves as a direct interchange for MerCruiser part numbers 35-803897Q1 and 8M0046752, and is cross-referenced with Sierra 18-7784, Mallory 9-37821, Volvo Penta 3855104, and GLM 24850.
- Installation: Fits inside the lower canister of the engine-mounted mechanical fuel pump.
- Complete Kit: Includes the filter element, spring, and rubber gaskets required for a full replacement.
- Fuel Compatibility: Engineered for use with gasoline-powered engines.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| MerCruiser | 35-803897Q1 |
| MerCruiser | 8M0046752 |
| MerCruiser | 35-8M0046752 |
| MerCruiser | 803897K1 |
| MerCruiser | 803897Q1 |
| MerCruiser | 11004T1 |
| MerCruiser | 11004T2 |
| MerCruiser | 11004A1 |
| MerCruiser | 11004Q2 |
| MerCruiser | 11004 |
| Sierra | 18-7784 |
| Mallory | 9-37821 |
| Volvo Penta | 3855104 |
| GLM | 24850 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
Compatibility for MerCruiser engines is specific to models equipped with an engine-mounted mechanical fuel pump. Please verify your serial number and fuel pump type.
| 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 the battery is disconnected. Place a suitable container below the fuel pump to catch any fuel spillage.
- Carefully unscrew and remove the lower canister of the mechanical fuel pump.
- Remove the old filter, spring, and rubber gasket. Note their orientation for correct reassembly.
- Clean the inside of the pump canister and housing, removing any sediment or debris.
- Install the new spring and filter element from the kit, followed by the correct matching rubber gasket.
- Securely screw the canister back onto the fuel pump. Hand-tighten firmly, but do not over-tighten.
- Reconnect the battery, prime the fuel system as per your engine's service manual, and check for any leaks before starting the engine.
Troubleshooting & FAQ
How do I know if this filter fits my engine?
This kit is for MerCruiser 2.5L, 3.0L, 3.7L, and 4.3L sterndrive engines from the 1980s–2000s that have a mechanical fuel pump mounted on the engine block. Check the compatibility table and verify your serial number and pump type. It does not fit engines with electric fuel pumps.
What are the signs my fuel filter needs replacing?
Common symptoms include engine hesitation, loss of power, random stalling, or difficulty starting. A visual inspection of the old filter may show dirt, debris, or a dark, clogged appearance.
What is the recommended replacement interval?
For optimal performance and engine protection, we recommend replacing your fuel filter annually or every 100 hours of operation, whichever comes first. Always consult your engine’s service manual for specific maintenance schedules.
The kit includes multiple rubber rings. Which one should I use?
This kit is designed to cover several fuel pump variations. Compare the new rings to your old one and use the ring that provides an identical match in diameter and thickness to ensure a proper, leak-free seal.
What’s the difference between this filter and an OEM part?
This is a high-quality aftermarket component engineered to meet or exceed original equipment manufacturer (OEM) specifications for fit, function, and filtration. It provides a reliable, cost-effective alternative to the original brand-name part.
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.
demos>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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