How to Install Water Pumps on a 1992 Yamaha 200 Horsepower Outboard Engine
- 1). Place the Morse control in neutral. Loosen the nut from the stud that faces downward at the leading edge of the lower unit at the tip of the cavitation plate. The cavitation plate is the flat horizontal plate above the prop. Do not remove this nut -- just loosen it until it has four to five threads holding it on. This nut will keep the lower unit from falling off as the rest of the nuts are removed.
- 2). Remove the two nuts on either side of the lower unit under the cavitation plate using a socket. Remove the trim tab using an Allen wrench. Remove the nut found under the trim tab using a socket.
- 3). Prepare to lower the unit, which is surprisingly heavy. Lay some rags or something soft for the unit to rest on. Dropping the lower unit on the ground can damage the bottom of the lower unit. Get a good hold on the cavitation plate and use the other hand to finish removing the first nut loosened. Lower the unit slowly.
- 4). Remove the two bolts in the water pump housing using a socket. Lift the housing up and off the shaft. Remove the impeller followed by a washer, the metal plate and two more washers. Install the new washers, followed by the metal plate the impeller rests on. Install the washer and the impeller followed by the metal housing. Tighten the two bolts with a socket.
- 5). Line up the driveshaft and gearshift rod in their holes as the lower unit is lifted. Install the nut in the front of the cavitation plate to secure it in place as the rest of the nuts are installed. Install the two nuts on either side of the unit and the one up above the trim tab and tighten all nuts securely with a socket. Install the trim tab and tighten with the Allen wrench.