Sierra 18-7815

Upgrade Your Marine Engine with Reliable Fuel Delivery

Keeping your boat's engine running smoothly starts with a dependable fuel system. The Sierra 18-7815 Fuel Pump Kit, cross-referenced as MC#1399-5137, steps in as a robust aftermarket solution designed for marine enthusiasts who demand performance without compromise. Crafted from high-grade materials, this kit ensures consistent fuel pressure and flow, even in harsh saltwater conditions where corrosion is a constant threat.

Unlike stock components that wear out from ethanol-blended fuels or prolonged idling, this pump kit features precision-engineered diaphragms and check valves that resist degradation. Boaters report fewer vapor lock issues and improved throttle response after installation, making it a go-to for weekend warriors and serious anglers alike.

Key Features That Set It Apart

• Durable Construction: Zinc-plated body and Viton seals withstand exposure to modern fuels, extending service life in demanding marine environments.
• Precise Fuel Output: Delivers exact pressure specs for optimal carburetor or EFI performance, preventing lean conditions that lead to engine knock.
• Complete Kit: Includes pump, gaskets, and hardware for a seamless replacement, minimizing downtime on the water.
• Easy Integration: Direct bolt-on design matches OEM mounting points, preserving your engine's original setup.
• Quiet Operation: Reduced pulsation for smoother fuel delivery, contributing to a quieter ride.

These elements combine to make the Sierra 18-7815 a smart investment, often outlasting generics by delivering consistent reliability season after season.

Perfect Fit for Popular Outboard Engines

This fuel pump kit shines in compatibility with a range of Mercury outboards, including models from the 90s through early 2000s. It's engineered to match the mechanical pump requirements of inline and V6 configurations, ensuring plug-and-play simplicity. Always cross-check your engine's serial number for the best match, as variations exist across model years.

Ideal for repowers or rebuilds, it restores factory-spec performance without the premium cost of genuine parts. Saltwater boaters appreciate its resistance to galvanic corrosion, a common pitfall in brackish waters.

Installation Insights for DIY Boaters

Swapping out a tired fuel pump doesn't have to mean a trip to the shop. With basic tools like wrenches, a fuel line disconnect tool, and fresh rags for cleanup, most installs wrap up in under an hour. Start by relieving system pressure, then disconnect lines and vacuum hose before unbolting the old unit.

Pro tip: Inspect fuel lines for cracks while you're in there—aged rubber can sabotage even the best new pump. Prime the new diaphragm by cycling it manually a few times, and use thread sealant on fittings to prevent leaks. Fire up the engine on muffs first to verify flow before hitting the water.

"Switched to this kit on my '98 Merc 150, and it's been flawless through two summers of heavy trolling."

—Satisfied Captain, Great Lakes

Maximize Longevity with Smart Maintenance

To get the most from your Sierra 18-7815, integrate it into a proactive fuel system routine. Flush with stabilizer-treated fuel at layup, and add a water-separating filter upstream to trap moisture. Monitor for symptoms like hard starts or black smoke, which signal diaphragm wear.

In ethanol-heavy regions, opt for non-oxy fuels when possible, or use additives to combat gumming. Annual inspections catch issues early, keeping your outings interruption-free.