Key Features of the Sierra 18-7341 Fuel Pump
Engineered as a precise replacement for Yamaha OEM part #66K-13907-00, this Sierra fuel pump delivers reliable fuel delivery to keep your outboard running smoothly. Crafted with high-grade materials, it resists corrosion from saltwater exposure and handles the rigors of marine environments. The diaphragm design ensures consistent pressure and flow, preventing engine hesitation or stalling during critical moments on the water.
- Direct bolt-on fit for seamless installation without modifications.
- Precision-machined components for optimal fuel metering.
- Enhanced diaphragm durability to withstand ethanol-blended fuels.
- Compact design that integrates perfectly into tight engine compartments.
- Meets or exceeds OEM specifications for performance and longevity.
Why Upgrade to Sierra 18-7341 for Your Yamaha Outboard
Boat owners trust Sierra parts for their balance of quality and value. This fuel pump addresses common pain points like vapor lock in hot conditions or inconsistent idling caused by worn factory pumps. By maintaining steady fuel pressure—typically around 3-7 PSI depending on your model—it supports efficient combustion, better fuel economy, and reduced emissions. Whether you're trolling for fish or powering through choppy waves, it keeps your engine responsive and ready.
Unlike generic imports, Sierra's engineering focuses on marine-specific demands, including vibration resistance and thermal stability. Regular use in harsh conditions shows it outlasting stock pumps by handling pulsations from the crankcase without premature failure.
Easy Installation Guide and Pro Tips
Swapping out your old fuel pump takes under an hour with basic tools. Start by relieving system pressure, disconnecting fuel lines, and removing the mounting bolts. Inspect hoses and filters for wear while everything's accessible—replace if cracked to avoid future leaks. Prime the new pump by cycling the key before firing up to purge air.
Pro Installation Tips
- Work in a well-ventilated area and use fuel-rated clamps on lines.
- Apply marine grease to mounting threads for corrosion protection.
- Test for leaks at idle and under load after install.
- Pair with a fresh fuel filter to maximize system life.
Common mistake: Skipping the air bleed, which leads to hard starts. Follow these steps for a hassle-free upgrade.
Signs Your Fuel Pump Needs Replacement and How This Fixes It
Fuel delivery issues plague many outboards over time. Watch for black smoke on acceleration (rich mixture), hard starting after sitting, or loss of power at high RPMs. These stem from a failing diaphragm or clogged pulse line. The Sierra 18-7341 restores factory performance by providing pulse-responsive operation, eliminating lean spots and surge.
To diagnose: Pinch the output line while running—if RPMs drop, the pump is weak. This aftermarket solution revives engines without the OEM cost, often extending service intervals between rebuilds.
Maintenance Best Practices for Longevity
Extend the life of your Sierra fuel pump with simple habits. Run the engine weekly to circulate fuel and lubricate internals. Add a fuel stabilizer during storage to prevent varnish buildup. Annually, inspect the pulse hose for cracks—it's the Achilles' heel of these systems. In ethanol-heavy fuels, consider an inline filter upgrade to catch debris early.
Owners report 3-5 seasons of trouble-free use with proper care, far surpassing neglected OEM units.
Frequently Asked Questions
What Yamaha models is the Sierra 18-7341 fuel pump compatible with?
It's a direct replacement for Yamaha #66K-13907-00, typically found on select 2-stroke outboards. Always cross-reference your engine's serial number with the latest application data for exact fitment.
How do I know if my outboard fuel pump is failing?
Look for symptoms like intermittent stalling, poor acceleration, or fuel leaks around the pump. A simple test: Disconnect the pulse line—if fuel stops flowing, it's likely bad.
Does this pump work with ethanol-blended gasoline?
Yes, its robust diaphragm resists degradation from E10 and similar blends, but use stabilized fuel for best results in storage.
Is installation DIY-friendly for beginners?
Absolutely—with basic wrenches and safety precautions, most complete it in 30-45 minutes. No special tools required beyond fuel line disconnects.
What's the expected lifespan of the Sierra 18-7341?
With proper maintenance, it lasts 3-5 years or 500+ hours, depending on usage and fuel quality.
Can I use this pump on carbureted or EFI Yamaha engines?
Primarily for carbureted models using pulse-operated designs. Confirm your system's requirements before installing.
Does it maintain the same fuel pressure as the OEM?
Yes, it matches factory specs for reliable operation across your engine's RPM range.
Fuel Pump.
See Sierra's catalog for current application information.
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