Impeller for Yamaha/Mariner 25-30 HP – High-Durability Water Pump Impeller

The 52.400.04 impeller is intended for Yamaha and Mariner two-stroke outboards in the 25-30 HP range. It replaces the original water pump impeller (Yamaha OEM 689-44352-02, equivalent Mercury 47-84797M) and restores full cooling capacity. For these higher horsepower engines that often power larger boats, effective cooling is critical to preventing damage. This impeller is made from a special compound that withstands high RPM, heat, and exposure to saltwater.
With its 6 sturdy blades, the impeller provides a generous flow of water to the engine’s cooling passages, even when running at full throttle or carrying heavy loads. Installation is straightforward, as the impeller fits perfectly into the engine’s existing water pump housing with no modifications needed. Replacing the impeller with a new one greatly reduces the risk of cylinder overheating and ensures smooth engine operation during long runs.
For any owner of a Yamaha/Mariner 25-30 HP engine, this impeller is an important maintenance investment. Regular inspection and replacement of the impeller (every season or ~100 running hours) will ensure your engine remains reliable and you stay worry-free on the water.

• Application: Ideal for mid-sized motorboats, fishing vessels, and RIBs equipped with a 25-30 HP Yamaha/Mariner two-stroke outboard. The impeller keeps cooling steady during high-speed operation and extended journeys.
• Recommendation: Suitable for vessels around 4–6 meters in length powered by Yamaha/Mariner 25-30 HP outboards. Replace the impeller annually or every ~100 engine hours to ensure maximum cooling efficiency and avoid costly repairs.