2009 LOWE SS204 25in logs.

Pontoon motor cavitation. Water disturbance from the pontoons can also cause it on some toons. First it can physically damage the propeller. Do you know the difference between cavitation and ventilation.

Pontoon Motor Cavitation I have just purchased a new 18 ft pontoon with a new Honda 50 hp outboard. Its a plague of pontoon boats and why merc invented Big Foot motors. Water disturbance from the pontoons can also cause it on some toons.

The motor wants to cavitate after getting up to 5000 rpms. Cavitation is bad for three reasons. Should get a smooth flow from bottom of mounting box across cavitation plate-like air over an airplane wing.

It has a top speed of approximately 36 mph at 5600 rpm or so with 4 person load. That leaves me to place my passengers on the L-shaped lounger across from the helm. Cavitation plate on motor should be even with bottom of mounting box.

Cavitaion usually occurs as a result of damage and youll feel it in the form of vibrations. Standard props are pitched too steep for the slow speeds 20-25mph at full throttleand they run on the edge of cavitation. Cavitation wastes energy makes the propeller noisy as the vapor bubbles collapse and most seriously erodes the props surface due to localized shock waves against the blade surface.

Normally cavitation occurs when the prop is too close to the surface of the water. The propmotor setup seems to be good. Working on getting the prop right went from 19P to 15P to 13P.