Regular inspection and replacement of impellers keep your outboard in ship-shape Impellers are the heart of an engines cooling system and require regular inspection and replacement under normal operating conditions. Running through silty or sandy water or running a pump dry can ruin an impeller quickly and cause the engine to overheat. It is important to monitor cooling water outflow and replace the impeller at the first signs of reduced outflow.Sierra engineers their replacement impellers to meet or exceed OEM specifications. Boaters and technicians can be assured that a Sierra impeller will fit right and restore function to manufacturer specifications. Because unexpected failures can happen, it is important to have a spare onboard to save the day. Key Features Impeller is engineered to meet or exceed manufacturer specifications OEM fit makes installation straight forward Having a spare can save the afternoon and saves having to make a trip to the parts store. The Sierra Engine Parts Selector In addition to impeller kits, 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.ApplicationOEM Part NumberOEM Part NumberSierra Part Number18-306818-3069GLM8990089910Mallory9-45601, 9-45601-109-45602, 9-45602-10Mercury Marine—47-81423M, 47-97108M, 47-82824MYamaha Outboard6H4-44352-00-00, 6H4-44352-02-00, 6H4-44352-01-00697-44352-00-00, 6H3-44352-00-00