How to Replace the Water Pump on an 35 HP Evinrude Outboard

by Will Charpentier

A neglected water pump means your 35 hp Evinrude won't perform as well as one that receives a bit of TLC -- tender loving care. Each time you use your motor, inspect the water intake grate and remove any aquatic flora and fauna that may block it. During the boating season, check your water pump's condition after the first 20 hours of operation and then again at 100 hours, cleaning, adjusting and lubricating the pump as needed. Replace the water pump, if necessary, at the end of the season during your regular "winterization" process.

Remove the four bolts from the water pump cover with a thin-walled, 5/8-inch socket and slide the cover off the driveshaft. Pull the impeller drive pin from the driveshaft and slide the impeller plate off the driveshaft. Remove any remaining gasket material or sealant from the plate and the lower unit. Remove the water tube grommet from atop the pump housing.

Apply gasket sealing compound to the impeller housing O-ring, the water tube grommet and the outer rim of the metal casing of the new driveshaft seal. Install the seal atop the water pump housing with the lips of the seal facing toward the impeller. Lightly coat the inner surface of the water tube grommet with white marine grease, and fit the O-ring onto the large bore atop the water pump housing and the grommet to the water tube.

Apply gasket sealing compound to the rim of the impeller insert, then install it in the water pump housing with the small bleed hole toward the water tube. Lightly coat the impeller insert with lower unit gear lubricant and set the impeller on the insert while you rotate the impeller clockwise.

Squeeze a thin bead of gasket sealing compound onto the mating surfaces of the lower unit and the impeller plate. Slide the impeller plate down the driveshaft, onto the lower unit. Dab a spot of needle bearing grease on the impeller drive key and push the pin to the slot on the driveshaft. Slide the impeller housing down the driveshaft while turning the driveshaft clockwise to align the impeller over the drive key, and seat the impeller and housing against the impeller plate.

Apply a bead of thread locker to the threads of the four bolts for the water pump housing, thread them back into place and tighten them to a torque of 60 to 84 inch-pounds with a torque wrench.

Items you will need

  • 5/8-inch socket, thin wall
  • Gasket sealing compound
  • White marine grease
  • Lower unit gear lubricant
  • Needle bearing grease
  • Thread locker
  • Torque wrench

References

  • "Evinrude Repair Manual -- 2.5 to 250 HP Models, 2001-2009"; Seloc; 2009

About the Author

Will Charpentier is a writer who specializes in boating and maritime subjects. A retired ship captain, Charpentier holds a doctorate in applied ocean science and engineering. He is also a certified marine technician and the author of a popular text on writing local history.