Sierra 10-Micron Fuel/Water Separator Filter for Yamaha MAR-FUELF-IL-TR — High Capacity 90 GPH, Medium (6")

The Sierra 18-7866 is a high-capacity 10-micron fuel/water separator built to remove emulsified water and fine particles from gasoline while delivering up to 90 gallons per hour to Yamaha fuel systems.

Designed as a direct replacement for Yamaha MAR-FUELF-IL-TR, this Sierra filter combines a fine 10-micron media with high flow capacity and rugged construction to protect sensitive inboard, sterndrive, and outboard fuel injection components. It’s intended for marine applications where water contamination and fine particulate can damage pumps and injectors.

How effectively does this filter remove water and particles?

The 18-7866 uses media engineered to separate emulsified water from gasoline and capture small particles down to 10 microns. Sierra specifies removal of over 99.8% of emulsified water and more than 90% efficiency at 10 microns, giving strong protection for modern fuel systems without restricting flow.

• Water separation: >99.8% emulsified water extraction
• Particle filtration: >90% efficiency at 10 microns
• Flow capacity: rated to 90 GPH to support high-demand engines
• Designed for gasoline fuel systems used in marine environments

Will the Sierra 18-7866 fit my Yamaha MAR-FUELF-IL-TR application?

This unit is made as a direct-replacement size and specification for Yamaha MAR-FUELF-IL-TR applications and uses a universal mount approach for many installations. Confirm physical dimensions and connection type on your engine or fuel rail to ensure compatibility before purchase.

• Replacement for Yamaha MAR-FUELF-IL-TR
• High-capacity 6" (152.4 mm) filter size
• Universal fit considerations—check fittings and bracket space
• Suitable for inboard, sterndrive, and outboard systems

How do I install and maintain this fuel water separator?

Installation is straightforward when you match inlet/outlet fittings and mounting orientation; follow engine-maker recommendations for bleed and priming procedures. Regular inspection and timely replacement keep flow and separation performance optimal—replace per your service intervals or when water/contaminant build-up is detected.

• Mount on a secure bracket with correct flow direction
• Prime and bleed the fuel system after replacement
• Inspect for water or sediment regularly; change when contaminated
• Follow engine manufacturer intervals or seasonal service schedule

What performance can I expect on high-demand engines?

With a 90 GPH rating, this separator supports engines that require substantial fuel flow while maintaining fine filtration and water removal. The high-capacity design balances protective filtration with the flow needed by modern, high-horsepower outboards and sterndrives.

• Rated flow: 90 gallons per hour for high-demand use
• Balanced media for minimal pressure drop at rated flow
• Protects fuel pumps and injectors from water and particulates
• Engine-friendly design suitable for marine environments

Who is this for: The Sierra 18-7866 is aimed at boat owners, mechanics, and fleet managers who run Yamaha-equipped inboard, sterndrive, or outboard engines and need reliable water separation and fine-particle filtration without sacrificing flow. It’s appropriate for recreational and commercial vessels that demand consistent fuel cleanliness to protect modern fuel injection systems and sustain engine performance.