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4.4 Water Testing
CHECKING FOR CAVITATION
The initial outboard height setting should be close to the optimum setting for the outboard. However,
because of the hull design of some boats, obstructions, or imperfections in the hull ahead of the water
intake, adjustments may be required to prevent cavitation at running speeds. When operating the boat, the
outboard driveshaft housing should be vertical, or tilted toward the boat, when planning to provide a
scooping angle on the water intake. Tilting the outboard out beyond a vertical position reduces the scoop
angle and can cause impeller slippage and cavitation.
WARNING
：
If the angle of the boat transom does not allow the driveshaft housing to be positioned vertical, a wedge kit
should be installed behind the transom brackets to increase the tilt-in angle.
CAUTION:
Slight cavitation in sharp turns and rough water is acceptable, but excessive cavitation is harmful to the
outboard and should be avoided. Test runs the boat. If cavitation occurs(air enters the pump), the first thing
to try is lowering the outboard mounting height.
If cavitation still exists after lowering the outboard, it may be helpful to seek advice from the boat
manufacturer.
