In-line Fuel Filter for Mercury EFI 30-350 HP 18-7718

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

This in-line fuel filter is designed for a wide range of Mercury/Mariner 4-Stroke outboard engines from 30 to 350 HP, including EFI and Verado models. It also fits select Yamaha 2-Stroke and 4-Stroke outboards, ensuring broad compatibility for maintaining a clean fuel system.

It serves as a direct replacement for multiple OEM and aftermarket part numbers, including Mercury 35-879885Q, 35-879885T, 35-879885K, Sierra 18-7718, and Yamaha 6G1-13621-A1-00.

• Installation Method: Installs under the engine cowl, in-line with the fuel hose.
• Fuel Compatibility: Approved for use with gasoline and ethanol-blended fuels (e.g., E10).
• Filtration Performance: Features a 20–30 micron filter element to effectively remove contaminants.

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.

Mercury/Mariner

Yamaha

Technical Specifications

Package Contents

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

Installation Guide

1. Safety First: Ensure the engine is off and cool. Work in a well-ventilated area and have a fire extinguisher nearby.
2. Locate the Filter: Remove the engine cowl to locate the existing in-line fuel filter.
3. Prepare for Removal: Place a rag or container under the filter to catch any spilled fuel.
4. Disconnect Fuel Lines: Carefully loosen the clamps and disconnect the fuel hoses from both ends of the old filter. Note the direction of the fuel flow arrow.
5. Install New Filter: Connect the new filter, ensuring the fuel flow arrow points in the correct direction (towards the engine).
6. Secure Connections: Securely fasten the fuel line clamps on the new filter's barbs.
7. Prime and Check: Prime the fuel system using the primer bulb until firm.
8. Inspect for Leaks: Visually inspect the filter and connections for any signs of fuel leaks before starting the engine.

Troubleshooting & FAQ

Q: How do I confirm this filter fits my engine?
A: First, check the Part Number Cross-Reference table to see if it matches your existing part number. Next, review the Compatible Engine Models tables to ensure your specific make, model, and year range are listed.

Q: Where does this filter get installed?
A: This is an under-cowl, in-line filter. It connects directly into the 8mm fuel line inside the engine housing.

Q: What are the signs that my fuel filter needs replacement?
A: Common symptoms include engine hesitation, sputtering, rough idling, or a loss of power, especially at high speeds. A visual inspection may also show debris in the clear housing, indicating it's time for a replacement.

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.