Sierra 18-7967 Mercury Fuel Water Separator Filter With Sensor

Protect Your Outboard Engine with Reliable Fuel Filtration

Nothing disrupts a day on the water like fuel-related issues—water contamination, debris buildup, or sensor failures that leave you stranded. The Sierra 18-7967 steps in as a dependable solution, engineered specifically for Mercury outboards to keep fuel clean and engines running smoothly. This filter doesn't just meet specs; it delivers peace of mind by separating water from fuel while monitoring for potential problems, ensuring your boating adventures stay uninterrupted.

Boaters know the frustration of murky fuel tanks after heavy rain or long storage periods. With its integrated sensor, this unit alerts you early to water accumulation, preventing corrosion, injector clogs, or worse—complete engine failure. It's the kind of proactive protection that turns potential headaches into routine maintenance.

Performance Specs That Handle Real-World Demands

Built to support engines up to demanding flow needs, this filter maintains a robust 90 gallons per hour (GPH) throughput, ideal for high-performance outboards pushing through choppy waters or towing skiers. Its 10-micron filtration captures even the finest particles and emulsified water droplets that cheaper filters miss, safeguarding fuel pumps, carbs, and EFI systems.

• Flow Capacity: 90 GPH—plenty for most recreational and light commercial use without restricting power.
• Filtration Precision: 10 microns, striking the perfect balance between capturing contaminants and unrestricted flow.
• Integrated Sensor: Detects water levels instantly, compatible with Mercury's warning systems for on-dash alerts.

These aren't just numbers on a spec sheet; they're proven in salty bays, freshwater lakes, and everything in between, where consistent performance separates weekend warriors from serious anglers.

How the Water Separation Process Works

Fuel enters the filter housing, where hydrophobic media repels water while allowing hydrocarbons to pass. Suspended water coalesces at the bottom, triggering the sensor when levels rise. This design mimics nature's own separation but accelerates it for marine environments prone to condensation and splash-back. Result? Cleaner fuel reaching your engine, reduced wear on components, and longer intervals between services.

Compared to basic spin-on filters, the Sierra 18-7967's bowl-style setup lets you drain water manually during checks, extending filter life and minimizing waste. It's a smart upgrade for anyone who's dealt with the smoky starts or rough idles from contaminated fuel.

Seamless Installation for DIY Boaters

Swapping out your old filter is straightforward with basic tools—no special rigging required. Locate the existing unit on your fuel line (typically near the primer bulb or engine-mounted), disconnect fittings, and mount the new one in the same orientation. Pro tip: Use thread sealant on NPT threads and double-check O-ring seating to avoid leaks. The sensor plugs right into the factory harness, preserving your boat's electronics without rewiring.

Most installs take under 30 minutes, even for those new to marine mechanics. Always prime the system afterward and run the engine on a hose to bleed air. If you're trailering frequently, position it for easy access during pre-launch inspections.

Maintenance Tips to Maximize Longevity

Inspect monthly or every 50 hours of runtime—whichever comes first. Drain any water via the petcock, clean the bowl if algae appears, and replace the element when pressure drops or the sensor trips repeatedly. In ethanol-blended fuels, swap annually to combat gumming. Pair it with a quality fuel stabilizer for off-season storage, and you'll sidestep 90% of fuel system woes.

Owners report this filter outlasting generics by double the time, thanks to durable construction that resists cracking in UV exposure or vibration from rough seas.

Why Sierra Stands Out in Marine Aftermarket

Sierra's reputation stems from reverse-engineering OEM designs with enhancements like corrosion-resistant housings and precise sensor calibration. It's not a knockoff—it's a refined alternative that matches or exceeds factory performance at a fraction of dealer costs. Boaters upgrading from worn Mercury originals rave about the drop-in fit and reliable alerts that catch issues before they escalate.

"Finally, a filter that doesn't false-alarm but catches real water buildup. My 150hp Merc purrs like new." – Seasoned bay fisherman