The maintain schedule because that the 150-hp Mercury outboard engine calls for replacing the water pump"s impeller after ~ every 100 hrs of operation, or once a year. Unlike many of Mercury"s larger motors, the reduced unit discovered on this version is equipped v a water pump housing that provides a replaceable cartridge insert. The cartridge insert, new gasket and a brand-new impeller are component of the forced pump replacement kit, in addition to a new housing and face plate.

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Items girlfriend will require

Pump replacement kit

Adjustable wrench

2 tiny pry bars

Putty knife

White naval grease

Gasket sealing compund

Torque wrench


Lift the centrifugal slinger off the driveshaft. Remove, v an adjustable wrench, the two 3/8-inch nuts, the one 1/4-inch nut, the bolt and their washers that organize the water pump cover come the optimal of the reduced unit.


Use two little pry bars, one in ~ the front and also one at the rear of the pump cover, to break the cover and its gasket totally free from the lower unit. Lift the water pump cover and also gasket off the driveshaft. Discard the gasket and scrape any remaining gasket product from the lower unit"s surface ar with a putty knife.


Lift the impeller up and off the driveshaft. Remove the Woodruff an essential from the driveshaft keyway and tuck the crucial in her pocket until needed. Lift the confront plate native the driveshaft; discard the faceplate.


Inspect the water pump cover for cracks, distortion, grooves or turbulent surfaces. Change the cover, if necessary.


Slide the instead of gasket and also face plate down the driveshaft and also onto the water pump base. Table of contents the gasket and also place the dowel pins on the pump base. Slide a new face plate-to-water pump cover gasket top top the face plate and index it through the dowel pins.


Remove the Woodruff key from your pocket, dab a bit of white maritime grease top top its behind edge and also insert the in the keyway top top the driveshaft. On slide the pump impeller under the driveshaft, to adjust so that slips end the Woodruff key. Press the impeller right into place.


Apply a slim coating the gasket sealing link to the outer diameter the a new pump cartridge insert, align the insert tab v the slot top top the pump cover and press the insert into the cover. Wipe off any excess sealant. Lubricate the inner surface of the pump cover with a slim coat that white marine grease..


Slide the cover under the driveshaft and over the impeller press on the cover while rotating the driveshaft clockwise till the cover seat on the face plate. Reinstall the three nuts and also the bolt the secure the water pump in place, tightening the nuts come 50 inch-pounds and also the bolt to 35 inch-pounds with a talk wrench, utilizing a crossing pattern.

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Apply a thin coat that white marine grease to the inside of the water tube seal. Slip the centrifugal slinger down the driveshaft and against the pump cover.