Water Separating Fuel Filter for MerCruiser Gen III Cool Fuel Systems – 5.0L, 5.7L, 6.2L, 8.1L and 8.2L
Water Separating Fuel Filter for MerCruiser Gen III Cool Fuel Systems – 5.0L, 5.7L, 6.2L, 8.1L and 8.2L is backordered and will ship as soon as it is back in stock.
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Water Separating Fuel Filter for MerCruiser Gen III Cool Fuel Syste...
Water Separating Fuel Filter for MerCruiser Gen III Cool Fuel Systems – 5.0L, 5.7L, 6.2L, 8.1L and 8.2L is backordered and will ship as soon as it is back in stock.
Product Details
This water-separating fuel filter is designed as a replacement filter element for selected MerCruiser gasoline engines equipped with the Generation III Cool Fuel System. It helps separate water and trap contaminants from the fuel supply before they reach the engine, supporting clean fuel delivery and reliable operation.
The filter is listed for MerCruiser 5.0L, 5.7L, 6.2L, 8.1L and 8.2L applications using the Gen III Cool Fuel housing. Always compare the housing, existing filter and applicable engine service information before ordering.
It replaces or cross-references Mercury references 8M0093688, 35-866171A01 and 866171A01. Sierra 18-7977 is listed as an aftermarket cross-reference.
- Replacement filter element for the Gen III Cool Fuel system.
- Designed to separate water and filter fuel-system contaminants.
- Installs into the existing compatible fuel-cooler/filter housing.
- This listing is for the filter element only; additional service parts are not included unless specifically stated by the seller.
Part Number Matrix
Use these references to compare the replacement filter with the part number shown on your existing component or service documentation.
| Brand | Part Number | Superseded By | Notes |
|---|---|---|---|
| Mercury | 35-866171A01 | 8M0093688 | OEM reference |
| Mercury | 866171A01 | 8M0093688 | OEM reference |
| Mercury | 8M0093688 | Current OEM reference | |
| Sierra | 18-7977 | Aftermarket cross-reference |
Engine and Model Compatibility
The applications below are associated with MerCruiser Gen III Cool Fuel configurations. Compatibility depends on the exact fuel-system housing and engine configuration, so confirm the existing filter and applicable service information before installation.
| Brand | Model | Rated HP | Stroke | Listed Years | OEM Reference | System |
|---|---|---|---|---|---|---|
| MerCruiser | 350 MAG MPI Alpha/Bravo | 300 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
| MerCruiser | 350 MAG MPI Horizon Alpha/Bravo | 300 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
| MerCruiser | 350 MAG MPI Horizon MIE | 300 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
| MerCruiser | 350 MAG MPI MIE | 300 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
| MerCruiser | 370 MPI | 370 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
| MerCruiser | 496 MAG | 375 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
| MerCruiser | 496 MAG H.O. | 425 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
| MerCruiser | 5.0 MPI Alpha/Bravo | 260 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
| MerCruiser | MX 6.2L MPI Alpha/Bravo | 320 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
| MerCruiser | MX 6.2L MPI Horizon Alpha/Bravo | 320 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
| MerCruiser | MX 6.2L MPI Horizon MIE | 320 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
| MerCruiser | MX 6.2L MPI MIE | 320 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
| MerCruiser | 8.1L Inboard | 375 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
| MerCruiser | 8.1L Inboard H.O. | 420 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
| MerCruiser | 8.2L | 380–430 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
| MerCruiser | 5.7L MPI TowSport with Gen III | 350 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
| MerCruiser | 8.1L TowSport, Base | 375 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
| MerCruiser | 8.2L MAG, Base Model | 380 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
| MerCruiser | 8.2L MAG, H.O. Model | 430 | 4-Stroke | 2004–2015 | 8M0093688, 866171A01 | Gen III Cool Fuel |
Technical Specifications
- Product Type
- Water-separating fuel filter element
- Application
- MerCruiser Gen III Cool Fuel system
- Fuel Type
- Gasoline
- Installation
- Installs inside the compatible fuel-cooler/filter housing
- Filtration Rating
- 15 micron, as listed for this replacement filter
- Connection
- Integrated into the compatible fuel-cooler housing
- Replacement References
- 8M0093688, 35-866171A01, 866171A01
- Aftermarket Cross-Reference
- Sierra 18-7977
- Product Status
- Aftermarket replacement; not an OEM-branded component
What's in the Box
- 1 x Water-separating fuel filter element
This product is listed as a single filter element. Filter disks, seals, gaskets, covers and other service components are not included unless they are specifically stated in the seller's package description.
Installation Notes
- Disconnect the boat's battery and observe all applicable marine fuel-system safety precautions.
- Relieve fuel-system pressure according to the engine manufacturer's service procedure.
- Locate the compatible Gen III Cool Fuel module and clean the area around the cover before opening the housing.
- Remove the housing cover according to the applicable service manual.
- Remove the old filter element and inspect the housing, seals and filter disk for damage or contamination.
- Do not reuse damaged seals or other service parts. Replace them separately if required by the service procedure.
- Install the new filter element in the correct orientation and position.
- Reinstall the cover and tighten it to the manufacturer's specified torque. Do not overtighten.
- Reconnect the battery, prime the fuel system according to the engine manual and inspect carefully for leaks before operating the engine.
Troubleshooting and FAQ
How do I confirm that this filter fits my MerCruiser engine?
Confirm that your engine uses the Generation III Cool Fuel system and that the existing filter or service documentation references 8M0093688, 35-866171A01, 866171A01 or the applicable cross-reference. Model, year and horsepower alone are not sufficient if the fuel-system housing differs.
What is the relationship between 8M0093688 and 866171A01?
8M0093688 is listed as the superseding Mercury reference for 35-866171A01 and 866171A01. Confirm the number and physical configuration of the filter in your application before ordering.
Is this a complete filter service kit?
No. This listing is for one replacement filter element. A filter disk, seals or gaskets are not included unless separately stated in the package description.
How often should the filter be replaced?
Follow the maintenance interval in your engine or boat service manual. Replacement may also be necessary sooner if the engine shows fuel restriction symptoms or if water or contamination is found in the fuel system.
What are common signs of a restricted fuel filter?
Possible symptoms include hesitation, loss of power, stalling, difficult starting or rough running. These symptoms can have several causes, so inspect the complete fuel system and follow the engine manufacturer's diagnostic procedure.
Is this an OEM Mercury filter?
No. This listing is for an aftermarket replacement filter intended for applications associated with the listed Mercury references.
Are seals or gaskets included?
No seals or gaskets are included with this single filter-element listing. Inspect the existing service parts and obtain replacements separately if required.
Safety and Important Information
- Verify the filter housing, existing filter and applicable part references before purchase.
- Use only with a compatible Gen III Cool Fuel configuration.
- Relieve fuel pressure and work in a well-ventilated area away from ignition sources.
- Check carefully for fuel leaks after installation and before operating the engine.
- Professional installation is recommended when the applicable service procedure is not available.
About Sea Sierra
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