How to Replace the Water Pump on a 15HP Evinrude Outboard Motor

How to Replace the Water Pump on a 15HP Evinrude Outboard Motor

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Evinrude's recommended maintenance schedule for the water pump on its outboard motor requires a basic visual inspection after the first 20 hours of use, then at every 12 months or 100 hours of use, whichever comes first. Eventually, you'll need to replace the water pump on your 15 HP Evinrude, no matter how well it holds up and particularly if it overheats. When the time for replacement arrives, you'll find that installing the pump is straightforward.

Items you will need

  • 3/8-inch open-end wrench

  • Gasket sealing compound

  • White marine grease

  • Needle-bearing assembly grease

  • Torque wrench

Remove the four bolts holding the water pump cover onto the lower unit. Ease the cover upwards and off the driveshaft.

Pull the impeller drive pin out of the driveshaft. Slide the impeller plate up and over the end of the driveshaft. Scrape any remaining gasket material or sealant from the lower unit.

Apply gasket sealing compound to the rim of the outer metal casing of the driveshaft seal. Position the seal on the top of the pump housing with its lips facing toward the impeller. Apply gasket sealing compound to the O-ring for the impeller housing the outer rim of the water tube grommet. Insert the O-ring onto the large, round opening atop the water pump housing and insert the grommet on the smaller, round opening atop the housing. Apply white marine grease to the inside of the water tube grommet.

Apply gasket sealing compound to the outer rim of the pump's impeller insert. Place the insert into the pump housing, ensuring the small bleed hole faces the water tube. Apply a thin coat of motor oil to the insert and rotate the impeller clockwise, pressing the insert onto the impeller. Apply a bead of gasket sealing compound to the machined surfaces of the lower unit and the impeller plate. Fit the impeller plate down over the driveshaft and onto the lower unit.

Apply a small amount of needle-bearing assembly grease to the impeller drive key to hold it in its proper place on the driveshaft. Fit the impeller drive pin in the key-way slot in the driveshaft. Slip the impeller housing downward onto the driveshaft while turning the driveshaft clockwise to align the impeller with the key. Push the housing and impeller down against the impeller plate.

Apply thread-locking compound to the four water pump housing bolt threads. Thread the bolts into place and torque them to 60 inch-pounds.


  • Be cautious with the sealant when installing the impeller. Too much sealant could clog a cooling passage dry on an impeller contact surface, causing accelerated impeller wear.
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