How to Line up a Cavitation Plate With Norris Craft Boats

On Norris Craft boats, the ventilation plate's alignment can be problematic. When a boat's propeller ventilates, its tips are coming out of the water and dragging air from the surface down into the water in a mass of bubbles. If you line up the cavitation plate properly, the ventilation plate will help break up the ventilation bubbles that retard the forward movement of the propeller. The plate also gives you a needed visual reference for adjusting your outboard's height in the water, another factor that contributes to ventilation and cavitation.

Things You'll Need

  • 5/16-inch box-end wrench
  • 1/2-by-1/2 inch square wood stock
  • Wrench
Show More

Instructions

  1. Norris Craft With Jack Plate

    • 1

      Disconnect the negative cable of the battery before performing any maintenance work on the outboard motor to prevent electrical shock or accidental start up. Remove the nut from the negative post with a 5/16-inch box-end wrench. Lift the cable from the battery, move it outside of the battery box and close the lid of the battery box.

    • 2

      Thread the plug into the bottom of the rear of the splash well. Launch the boat. The boat should be loaded as it would normally be when you go boating.

    • 3

      Move the boat away from the launching ramp. Have an assistant move the vehicle and trailer from which the boat was launched to a safe parking area.

    • 4

      Bend over the stern of the boat while seated. Push the down switch, which controls the jack plate, to lower the motor until the bottom of the cavitation plate touches or is slightly below, the water.

    • 5

      Reconnect the negative battery cable.

    Norris Craft Without Jack Plate

    • 6

      Remove the nut from the negative battery post with a 5/16-inch box-end wrench. Take the cable off the battery, set it outside of the battery box then close the lid.

    • 7

      Cut a piece of 1/2-by-1/2 inch square wood stock so that it is as long as the engine's mounting bracket. Lay the wood stock -- called a rev stick -- along the top of the transom wall where you plan to mount the outboard if the outboard's driveshaft is longer than 15 inches.

    • 8

      Mount the engine onto the transom wall over the rev stick. Clamp the engine in place with the mounting clamps on the bracket.

    • 9

      Tilt the engine up so that the hole on the engine bracket lines up with the hole on the mounting bracket. Lock the motor into place with the engine's tilt lever.

    • 10

      Reconnect the negative battery cable.