Part Number: 47-30778
Sierra 18-30778 Water Pump Impeller Kit
Keep your outboard cooling system performing reliably with the Sierra 18-30778 Impeller Kit. Designed as a high-quality replacement for select OEM water pump systems, this kit restores proper water circulation and helps protect your engine from overheating during demanding use.
The water pump impeller is one of the most important maintenance components on any outboard. Over time, the rubber vanes can wear down, crack, or lose flexibility from heat, sand, and debris. Replacing the impeller at regular service intervals helps maintain proper cooling performance, protects internal engine components, and reduces the risk of costly repairs.
Manufactured using durable marine-grade materials, the Sierra 18-30778 is built to withstand harsh boating environments while delivering dependable long-term performance. Designed as a direct replacement for compatible lower units, it offers reliable fitment and straightforward installation.
Common Engine Fitments
The Sierra 18-30778 impeller kit is commonly used on select Yamaha and Mercury outboard engine applications, including:
- Yamaha F150 four-stroke outboards
- Yamaha F175
- Yamaha F200
- Yamaha F225
- Mercury 150HP four-stroke outboards with compatible pump systems
- Mercury 175HP four-stroke applications
These engines are frequently found on:
- Center consoles
- Bay boats
- Offshore fishing boats
- Bass boats
- Pontoon boats
Popular boat brands commonly equipped with these engines include:
- Sea Hunt
- Sportsman
- Key West
- Ranger
- Skeeter
- Bennington
Fitment can vary depending on lower unit design and model year, so confirming compatibility with part number 18-30778 before ordering is recommended.
Key Features
- High-quality marine water pump impeller kit
- Restores proper cooling system performance
- Helps prevent overheating and premature engine wear
- Compatible with select Yamaha and Mercury outboard applications
- Durable marine-grade materials for long service life
- Direct replacement for easy installation
Why Routine Impeller Service Matters
A worn impeller can reduce water flow long before complete failure occurs. Routine replacement helps maintain steady cooling performance, protects vital engine components, and reduces the risk of unexpected breakdowns on the water.
If you’re servicing a compatible Yamaha or Mercury outboard, the Sierra 18-30778 impeller kit delivers dependable cooling performance and OEM-style reliability you can trust.