Sierra 18-7846 Filter-Water Sep OMC 21M5

Water in your boat's fuel can spell disaster—engine sputters, corrosion, and unexpected breakdowns on the water. The Sierra 18-7846 fuel water separator steps in as a reliable guardian, stripping away over 98.8% of emulsified water from gasoline to keep your OMC 21M5 engine running smooth and strong. Designed for marine enthusiasts who demand performance without compromise, this filter delivers a robust 90 GPH flow rate, ensuring even the most power-hungry outboards stay fueled without restriction.

Engineered for Marine Demands

Crafted by Sierra Engine Parts, the 18-7846 isn't just another filter—it's a precision tool built to handle the harsh realities of boating life. Whether you're chasing horizons on a coastal cruiser or powering through rough inland waters, this separator tackles contaminants head-on. Its high-efficiency media captures tiny water droplets that standard filters miss, preventing phase separation and gelling that plague ethanol-blended fuels common today.

Choose Your Bowl: Clear or Metal

• Clear Bowls: Ideal for outboard motors and above-deck setups. Quick visual checks let you monitor water accumulation and fuel clarity at a glance, making maintenance a breeze during routine dockside inspections.
• Metal Bowls: Compliant with USCG regulations for below-deck installations, these flame-resistant bowls add an extra layer of safety in enclosed engine compartments. No compromises on protection or performance.

Selecting the right bowl type ensures your setup meets safety standards while optimizing accessibility for service. Pro tip: In high-humidity environments, pair with a dedicated water drain valve to extend service intervals.

Why It Outshines the Rest

Unlike basic inline filters, the Sierra 18-7846 combines separation efficiency with unrestricted flow. Boat owners report fewer filter changes and cleaner injectors, translating to longer engine life and fewer tow-back-to-marina moments. It's a direct fit for OMC 21M5 systems, blending OEM-quality filtration with aftermarket affordability. Real-world testing in salty air and variable temps confirms its durability—resisting corrosion that plagues lesser units.

Installation and Maintenance Insights

Swapping in the 18-7846 is straightforward for DIY mechanics: Mount securely, connect hoses with proper clamps, and prime the system to avoid air locks. Check the bowl weekly during the season, draining water as needed—especially after heavy rain or long storage. For peak performance, replace the element every 100 hours or annually, whichever comes first. This simple regimen keeps your fuel system pristine and your adventures uninterrupted.

Boost Your Boating Confidence

Investing in a fuel water separator like the Sierra 18-7846 means peace of mind on every outing. From weekend warriors to serious anglers, it's the upgrade that pays dividends in reliability. Keep water where it belongs—outside your engine—and let your OMC roar.