Mercury/Mariner 3.5–9.9 HP Impeller – OEM 6-Blade Cooling Turbine

This Mercury/Mariner 3.5–9.9 HP impeller is designed to maintain reliable cooling in the later generations of small 2-stroke engines. It covers models from the early 1980s through the end of the 9.9 HP 2-stroke era (and 15 HP, which often share the same water pump as the 9.9). With a 6-blade design and high-grade neoprene, the impeller provides ample water flow through the engine. This eliminates the risk of overheating even when running at full throttle or in hot climates. Your Mercury/Mariner motor will operate at optimal temperature, ensuring maximum power output and extended component life.

As an OEM equivalent (replacing Mercury original #47-68988 and #47-89980), this impeller fits flawlessly and performs just as well as the factory part. Installing it restores the original cooling efficiency – critically important if you notice a weak tell-tale stream or rising operating temperatures. The swap is quick with basic tools, and having this impeller as a spare gives you confidence on long outings. Manufacturers suggest that impellers in 2-stroke engines be replaced more frequently (every year or ~50–100 hours), since these engines produce more heat per cc and rely heavily on good cooling.

The Mercury/Mariner 9.9 HP two-stroke is legendary for its reliability and broad use – from small fishing boats to tenders and sailboat outboards. This impeller ensures those popular motors remain dependable. The same goes for the smaller 3.5, 4, 5, 6 HP units often used for short trips or as kickers. Whether you’re an angler on a lake or a coastal cruiser, replacing the impeller with this high-quality component will give you peace of mind. The impeller resists saltwater and fine debris from lakebeds, which is crucial when operating in diverse conditions.

• Next-Gen Small Engines: Specially suited for modern (1980s onward) Mercury/Mariner 2-stroke engines, where cooling must be efficient to handle higher power output for the displacement.
• 9.9/15 HP Two-Strokes: If you own a 15 HP 2-stroke Mercury/Mariner from the 80s/90s, this impeller is typically the same as the 9.9 HP’s – it provides the cooling needed for full power operation.
• No Power Loss: By keeping the engine cool, the impeller prevents “power fade” (loss of power due to overheating) – your motor will always deliver peak thrust.
• Mechanic-Approved: Many service shops use these CEF impellers for Mercury/Mariner repairs, thanks to their reliability and precise fit.
• Built for Any Water: Intended for use in both saltwater and freshwater – the material withstands corrosion and algae common in different waterways.