Replacement impeller for smaller Johnson/Evinrude outboards. Impellers are the heart of an engines cooling system. Running through silty or sandy water or running a pump dry can ruin an impeller quickly and cause the engine to overheat. Sierra offers replacement impellers engineered to meet or exceed manufacturers specifications. Boaters and technicians can have the confidence of a factory fit and function when using a Sierra impeller. Having a spare for unexpected failures can save the day. Key Features Impeller is engineered to meet OEM specifications Compatible with older 4hp—8hp Johnson/Evinrude outboards 18-3091 Application Guide ApplicationOEM Part NumbersGLM89500Johnson/Evinrude Outboard389576Mallory9-45205, 9-45214The Sierra Engine Parts SelectorIn addition to impellers, we offer a wide variety of other engine parts manufactured by Sierra. To see if we have the part you need, see ourEngine Parts Selector, where you can search by engine make, serial number and model or year of manufacture.