Sierra 18-7339 7339 Yamaha Outboard Electric Fuel Pump

Why Upgrade to the Sierra Electric Fuel Pump for Your Yamaha Outboard

Boat owners know the frustration of a sputtering engine mid-trip due to fuel delivery issues. The Sierra electric fuel pump steps in as a reliable fix, designed specifically for Yamaha outboards. This isn't just any replacement—it's built to handle the demands of marine environments, delivering consistent fuel pressure even under heavy loads or in choppy waters. With its robust construction, it helps prevent those dreaded no-start conditions caused by vapor lock or weak pumps, keeping you on the water longer.

Engineered for seamless performance, this pump ensures your outboard runs smoothly, whether you're trolling for bass or powering through offshore waves. Boaters rave about its longevity, often outlasting stock components thanks to superior materials and smart design choices.

Standout Features That Set It Apart

• Gerotor Positive Displacement Design: Unlike diaphragm pumps that wear out quickly, the gerotor mechanism provides steady, pulse-free fuel flow. This reduces cavitation and maintains optimal pressure for better combustion efficiency.
• Carbon Commutator: Lowers electrical amp draw, easing the burden on your battery and electrical system. It also suppresses radio frequency interference (RFI), so your marine electronics stay clear of static.
• Meets or Exceeds OEM Standards: Precision-machined internals match or surpass original equipment specs, ensuring drop-in compatibility without modifications.
• Corrosion-Resistant Build: Marine-grade materials withstand saltwater exposure, ethanol-blended fuels, and constant vibration—common culprits in fuel system failures.
• Compact and Lightweight: Easy to mount in tight engine compartments, saving space and weight for improved boat handling.

Perfect Fit for Yamaha Outboard Models

This pump serves as a direct replacement for common Yamaha outboard fuel systems, fitting a range of popular models from the 90s through modern VMAX and F-series engines. It's ideal for 2-stroke and 4-stroke setups where reliable priming and pressure are critical. Before installing, cross-check your engine's service manual to confirm compatibility, as fuel systems can vary by horsepower and year.

Pro tip: If your outboard has been sitting unused, this pump excels at purging stale fuel and air from lines during startup, minimizing dry-run damage.

Simple Installation Steps for DIY Boaters

Swapping out your old fuel pump doesn't require a marine mechanic. Here's a straightforward guide:

1. Disconnect the battery and relieve fuel pressure by running the engine dry or pinching lines.
2. Remove the old pump: Unclip electrical connectors, loosen hose clamps, and extract mounting bolts.
3. Install the new Sierra pump: Align fittings, secure hoses with fresh clamps, and torque bolts to spec (typically 5-7 ft-lbs).
4. Reconnect wiring, prime the system by cycling the key, and test for leaks at idle.
5. Monitor pressure with a gauge—expect 5-10 PSI depending on your model.

Total time: Under an hour for most setups. Always work in a well-ventilated area and have a fire extinguisher handy.

Boost Reliability and Avoid Common Fuel System Pitfalls

Fuel pumps fail from ethanol corrosion, clogged filters, or electrical shorts. Pair this Sierra unit with an inline filter and fresh ethanol-free fuel stabilizer for peak performance. Regular checks during annual servicing catch issues early—listen for whining pumps or erratic idle as warning signs.

Real-world benefit: Anglers report fewer breakdowns during multi-day trips, and tournament pros appreciate the consistent throttle response it delivers under sustained high RPMs.

Frequently Asked Questions