Fuel Filter – Fits Mercury/Mariner 75-300 HP Outboards & MerCruiser 4.5L/6.2L (Replaces 35-8M0122423, 35-8M0060041)
Fuel Filter – Fits Mercury/Mariner 75-300 HP Outboards & MerCruiser 4.5L/6.2L (Replaces 35-8M0122423, 35-8M0060041) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
U.S. orders usually arrive within 6–15 days, depending on stock location and destination.
International delivery times may vary due to customs processing.
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Fuel Filter – Fits Mercury/Mariner 75-300 HP Outboards & MerCruiser 4.5L/6.2L (Replaces 35-8M0122423, 35-8M0060041) is backordered and will ship as soon as it is back in stock.
Product Details
This high-quality aftermarket fuel filter is designed for selected Mercury and Mariner 75–300 HP outboards and MerCruiser 4.5L and 6.2L sterndrive engines. It supports a range of Mercury/Mariner 2-stroke and 4-stroke Optimax, Pro XS, and Verado applications, as well as specific MerCruiser engines identified by model and serial-number conditions. Always compare your engine model, year, serial number, original filter, and connection style before ordering.
This filter replaces Mercury part numbers 35-8M0122423 and 35-8M0060041. Additional cross-reference numbers commonly associated with this filter include Mercury 35-8M0020349 and 35-884380T, Sierra 18-7981, and Mallory 9-37970. Cross-reference numbers are provided for identification; confirm the physical specifications and application details before installation.
- Engineered for in-line fuel-system installation.
- Designed for gasoline fuel applications, including compatible ethanol-blended gasoline.
- Aftermarket replacement manufactured for comparable fit, form, and function to the referenced original part.
- Nominal filtration rating: 2 microns.
Part Number Matrix
Use the following references to compare the replacement filter with your original part. Part-number cross-references should be confirmed against the engine application and the physical filter before purchase.
| Brand | Part Number |
|---|---|
| Mercury | 35-8M0122423 |
| Mercury | 35-8M0060041 |
| Mercury | 35-8M0020349 |
| Mercury | 35-884380T |
| Sierra | 18-7981 |
| Mallory | 9-37970 |
Engine & Model Compatibility
The applications below represent the listed Mercury/Mariner outboard and MerCruiser engine coverage. Fitment may vary by model year, engine configuration, and serial number. Confirm the complete engine identification before ordering.
Mercury/Mariner outboards: Selected 75–300 HP 2-stroke and 4-stroke models manufactured approximately from 2003 through 2018, including the applications shown below.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | 3-Cylinder Optimax | 75 | 2-Stroke | 2004–2014 | 35-8M0122423 | 1.5L, 3.6255 bore |
| Mercury | 3-Cylinder Optimax | 80 | 2-Stroke | 2007–2014 | 35-8M0122423 | 1.5L, 3.6255 bore |
| Mercury | 3-Cylinder Optimax | 90 | 2-Stroke | 2004–2014 | 35-8M0122423 | 1.5L, 3.6255 bore |
| Mercury | 3-Cylinder Optimax | 115 | 2-Stroke | 2004–2014 | 35-8M0122423 | 1.5L, 3.6255 bore |
| Mercury | 3-Cylinder Optimax | 125 | 2-Stroke | 2006–2012 | 35-8M0122423 | 1.5L, 3.6255 bore |
| Mercury | 3-Cylinder Optimax Pro XS | 115 | 2-Stroke | 2004–2014 | 35-8M0122423 | 1.5L |
| Mercury | 4-Cylinder | 135 | 4-Stroke | 2006–2009 | 35-8M0122423 | |
| Mercury | 4-Cylinder | 150 | 4-Stroke | 2006–2018 | 35-8M0122423 | |
| Mercury | 4-Cylinder | 175 | 4-Stroke | 2006–2014 | 35-8M0122423 | |
| Mercury | 4-Cylinder Verado | 135–175 | 4-Stroke | 2006–2014 | 35-8M0122423 | |
| Mercury | 6-Cylinder Optimax | 200 | 2-Stroke | 2003–2018 | 35-8M0122423 | 3L, 3.6265 bore |
| Mercury | 6-Cylinder Optimax Pro XS | 200 | 2-Stroke | 2007–2018 | 35-8M0122423 | 3L, 3.6265 bore |
| Mercury | 6-Cylinder Optimax | 225 | 2-Stroke | 2003–2018 | 35-8M0122423 | 3L, 3.6265 bore |
| Mercury | 6-Cylinder Optimax Pro XS | 225 | 2-Stroke | 2004–2010 | 35-8M0122423 | 3L, 3.6265 bore |
| Mercury | 6-Cylinder Optimax | 250 | 2-Stroke | 2004–2014 | 35-8M0122423 | 3L, 3.6265 bore |
| Mercury | 6-Cylinder Optimax Pro XS | 250 | 2-Stroke | 2006–2010 | 35-8M0122423 | 3L, 3.6265 bore |
| Mercury | 6-Cylinder Optimax | 300 | 2-Stroke | 2015–2018 | 35-8M0122423 | 3L, 3.6265 bore |
| Mercury | 6-Cylinder | 200 | 4-Stroke | 2005–2014 | 35-8M0122423 | |
| Mercury | 6-Cylinder | 225 | 4-Stroke | 2005–2014 | 35-8M0122423 | |
| Mercury | 6-Cylinder | 250 | 4-Stroke | 2005–2014 | 35-8M0122423 | |
| Mercury | 6-Cylinder | 275 | 4-Stroke | 2005–2010 | 35-8M0122423 | |
| Mercury | 6-Cylinder | 300 | 4-Stroke | 2007–2014 | 35-8M0122423 | |
| Mercury | 6-Cylinder Verado | 200–300 | 4-Stroke | 2005–2014 | 35-8M0122423 | 3.0L |
| Mercury | Verado L4/L6 | Within 75–300 HP range | 4-Stroke | Application-specific | 35-8M0122423 | Verify serial number; listed condition includes serial number 2B144122 and below. |
MerCruiser sterndrives: Compatible with specific 4.5L and 6.2L 4-stroke engines according to serial-number application.
| Brand | Model | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|
| MerCruiser | 4.5L engine | 4-Stroke | 35-8M0122423 | Serial number 2A456613 and newer |
| MerCruiser | 6.2L engine | 4-Stroke | 35-8M0122423 | Serial number 2A456613 and newer |
Technical Specs
- Product Type
- Fuel filter
- Installation
- In-line
- Filtration Rating
- 2 microns
- Fuel Type
- Gasoline
- Connection
- Direct-fit aftermarket replacement for the referenced applications
- Housing Color
- Red
- Fitting Type
- Screw-in
- Warranty
- 1 year against manufacturing defects under normal use
- Other Attributes
- Aftermarket replacement, OEM-style fit and function, compatible with listed gasoline and ethanol-blended gasoline applications
What's in the Box
- 1 x Fuel filter
Installation Notes
- Shut off the fuel supply and allow the engine to cool completely before beginning work.
- Locate the existing fuel filter along the fuel line between the fuel tank and the engine.
- Place absorbent rags or a suitable container beneath the filter to catch spilled fuel.
- Carefully disconnect the fuel lines from both ends of the old filter. Note the direction of fuel flow, usually indicated by an arrow on the filter housing.
- Unscrew or unclamp the old filter from its mounting bracket.
- Install the replacement filter with the fuel-flow arrow pointing in the correct direction.
- Securely reconnect the fuel lines and confirm that all fittings are properly seated.
- Restore the fuel supply and inspect every connection for leaks.
- Prime the fuel system according to the engine manufacturer's instructions. Start the engine and inspect the filter and connections again.
- Dispose of the old filter and fuel-soaked materials according to local environmental requirements.
Troubleshooting & FAQ
How often should this fuel filter be replaced?
For general maintenance, replacement is commonly recommended annually or every 100 operating hours, whichever comes first. Always follow the maintenance interval in your engine's service manual, especially when operating in contaminated or humid conditions.
What are the signs of a failing or clogged fuel filter?
Common symptoms include hesitation, reduced power, rough idling, difficult starting, or engine stalling. These symptoms can have several causes, so inspect the complete fuel system and consult the service manual before replacing parts.
Is this filter compatible with ethanol-blended fuels?
This filter is intended for compatible gasoline applications, including commonly used ethanol-blended gasoline. Confirm the fuel requirements and approved ethanol percentage for your specific engine before use.
Does this filter fit both 2-stroke and 4-stroke engines?
Yes, the listed applications include selected Mercury/Mariner 2-stroke Optimax models and 4-stroke models such as Verado and other listed configurations, along with specific 4-stroke MerCruiser 4.5L and 6.2L engines. Check the model, year, and serial-number conditions before ordering.
Is this an OEM filter?
No. This listing is for an aftermarket replacement filter. The referenced Mercury, Sierra, and Mallory numbers are identification and cross-reference numbers only; this product is not represented as an original branded OEM component.
How quickly is the product shipped?
Typical international transit is 5–15 days. Standard shipping is free, and expedited options may be available at checkout depending on destination.
What warranty and return coverage applies?
The filter is covered by a 1-year warranty against manufacturing defects under normal use. Returns are accepted under the applicable store policy, generally for unused products in their original condition. Contact support with your order details if assistance is needed.
Safety & Important Information
- Verify the engine model, year, serial number, original filter, fitting style, and fuel-flow direction before installation.
- Do not rely on horsepower alone to confirm fitment; model and serial-number conditions must also match.
- This is an aftermarket replacement, not an original OEM component.
- Work in a well-ventilated area away from sparks, flames, and other ignition sources.
- Professional installation is recommended when you are not familiar with marine fuel-system service.
About Sea Sierra
- Pro-Grade Standards — We supply marine replacement parts designed for dependable fit and real-world service conditions.
- Fast Global Fulfillment — Free standard delivery is available to most regions, with typical transit of 5–15 days.
- Manufacturer-Direct Value — Competitive pricing with attention to materials, fit, and quality control.
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