Sierra In-Line Fuel Filter 21-Micron Medium Replacement 90 GPH (18-7845)

The Sierra International 18-7845 medium fuel filter is a 21‑micron, high‑flow in-line replacement designed to protect outboard fuel systems while delivering up to 90 GPH to hungry marine engines.

Designed for recreational and professional boating, this Sierra fuel filter is a direct-fit replacement for several factory units, providing the same form, fit and function as the original equipment. It replaces Mercury part 35-802893Q and Yamaha part ABB-FUELF-IL-TR, and uses a medium 21‑micron filtration element to trap particles while allowing dependable fuel flow. The construction and thread pitch match OEM specifications so installation is straightforward on compatible systems.

How does this filter maintain fuel flow during high-demand operation?

Even when an engine requires large volumes of fuel, the 18-7845 maintains steady throughput. The housing and media are engineered to sustain up to 90 gallons per hour, minimizing the risk of starvation under load while still capturing contaminants.

• Rated flow: 90 GPH to meet high‑output engine needs
• Medium 21‑micron element balances capture and flow
• Compatible thread pitch and dimensions for secure installation

What contaminants will the 21‑micron media remove?

The 21‑micron rating captures a broad range of solid particles that can harm fuel injectors, carburetors or pump components. It does not claim to remove dissolved water or chemical contaminants, but it reduces dirt, rust and other particulates that accelerate wear and clog downstream components.

• Traps particles down to 21 microns in size
• Prevents debris-related clogs in fuel delivery components
• Helps extend service intervals for pumps and injectors when replaced per schedule

How do I confirm fitment with my Mercury or Yamaha engine?

Fitment is confirmed by matching OEM part numbers, thread pitch and physical length. Sierra 18-7845 is produced to replace Mercury 35-802893Q and Yamaha ABB-FUELF-IL-TR; check your engine service manual or existing filter markings to verify compatibility before purchase.

• OEM cross-references: Mercury 35-802893Q, Yamaha ABB-FUELF-IL-TR
• Thread pitch: 42690 to match factory fittings
• Long size dimension: 1105 mm (check mounting clearance)

How should this filter be used and maintained?

Install the filter following manufacturer instructions and replace it at intervals recommended for your engine and fuel type, or sooner if performance or fuel quality issues occur. Ethanol‑blended fuels can increase water absorption and loosen more particulate matter, so regular inspection is especially important with modern fuels.

• Install with correct thread pitch and torque per engine manual
• Inspect when servicing fuel systems or if engine runs rough
• Replace according to routine maintenance or when flow is restricted

Who is this for: The Sierra International 18-7845 is intended for boat owners, mariners, and service technicians who need a reliable, OEM‑equivalent medium fuel filter for Mercury or Yamaha outboards. It suits operators who prioritize uninterrupted fuel delivery for high‑demand engines and those using modern ethanol‑blended fuels that require vigilant filtration. Choose this filter when you need a direct replacement that preserves factory fit and maintains consistent fuel throughput while removing particulate contaminants.