In-Line Fuel Filter – Fits Mercury/Mariner 30-350 HP 4-Stroke Outboards (Replaces 35-879885Q, 35-879885T, 35-879885K)

In-Line Fuel Filter – Fits Mercury/Mariner 30-350 HP 4-Stroke Outboards

This high-quality in-line fuel filter is designed for Mercury and Mariner 4-stroke outboard engines ranging from 30 to 350 HP, including EFI, Verado, and Pro Verado models manufactured from 1996 and newer. It fits a wide variety of specific engine series, such as 40–60 HP 4-cylinder models, 75–115 HP (1.7L and 2.1L), and 150 HP EFI engines.

It serves as a direct replacement for Mercury part numbers 35-879885Q, 35-879885T, and 35-879885K. It also cross-references to other aftermarket and OEM parts, including Sierra 18-7718 and specific Yamaha part numbers.

• Installation: Installs under the cowl in-line with the fuel hose.
• Fuel Compatibility: Approved for use with gasoline and ethanol blends (e.g., E10).
• Connection: Features a 5/16" (8mm) push-on barb connection for simple installation.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Confirm your engine model/year in the table below. For Yamaha owners, here’s a guide to help you identify your engine’s serial/model: Yamaha Serial Number Guide. You can also review exploded diagrams to verify part numbers: Yamaha Parts Diagrams & Catalog.

Technical Specifications

Package Contents

• 1 x In-Line Fuel Filter (Replaces 35-879885Q / 35-879885T / 35-879885K)

Installation Guide

1. Ensure the engine is off and cool to the touch. If your engine has a procedure for relieving fuel system pressure, perform it now.
2. Locate the old fuel filter under the engine cowl. It will be installed in-line with the fuel hose.
3. Place a clean rag or shop towel underneath the filter to absorb any fuel that may spill.
4. Using pliers, carefully loosen and slide the clamps off both ends of the filter.
5. Note the direction of the arrow on the old filter, which indicates fuel flow. Gently twist and pull the fuel hoses off the filter barbs.
6. Remove the old filter from its mounting bracket if it has one.
7. Position the new filter, making sure the arrow on its housing points in the same direction of fuel flow (towards the engine).
8. Firmly push the fuel hoses onto the barbs of the new filter and secure them with the clamps.
9. Prime the fuel system by squeezing the primer bulb until it feels firm.
10. Carefully inspect the filter and its connections for any signs of leaks.
11. Start the engine and allow it to run for several minutes, then perform a final check for leaks before reinstalling the engine cowl.

Troubleshooting & FAQ

Q: How do I know if this filter fits my Mercury engine?
A: This filter fits most Mercury and Mariner 4-stroke outboards from 30 to 350 HP manufactured since 1996. To be certain, please check the tables above. Your engine may be identified by year or by a serial number (S/N) range, such as with the 75-115 HP 1.7L and 2.1L engines.

Q: What is the filtration rating, and why is it important?
A: This filter has a filtration rating of 20–30 microns. This level of filtration is crucial for protecting modern fuel injectors and sensitive engine components from microscopic debris and contaminants that can cause poor performance or damage.

Q: Is this filter compatible with ethanol-blended fuels?
A: Yes, it is fully compatible with gasoline and common ethanol blends like E10. The housing features sonically sealed end caps to prevent leaks and ensure durability with modern fuels.

Q: How often should I replace this fuel filter?
A: For best performance and to protect your engine, we recommend replacing the in-line fuel filter at least once a year or every 100 hours of operation, whichever comes first. This is a critical part of routine marine engine maintenance.

Q: OEM vs. Aftermarket?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.