View Full Version : 1988 Prostar 190 cavitates when pulling a skier and "turning"

09-05-2013, 04:10 PM
love the boat. BUT when the wife is at the end of the lake and turning for a return run (we always turn to the right), the boat "cavitates". It does NOT do it when she makes a W-I-D E turn, or when she is skiing (im at 185 lbs,,,she's alot less), or when im just getting out of the water.

I tested with two "known good" props, so thats not the issue.

Have validated that the direct drive is full of trans fluid.

Kinda thinking bad clutch plates, but its somewhat hard to beleive that it..because theres more drag/resistance when getting me out of the hole.

Based on the articles in this forum, im thinking to pull the direct drive over the winter months and rebuild.


09-05-2013, 04:23 PM
Cavitation (which is often confused with ventilation) is a phenomena of water vaporizing or "boiling" due to the extreme reduction of pressure on the back of the propeller blade. Many propellers partially cavitate during normal operation, but excessive cavitation can result in physical damage to the blade surface due to the collapse of microscopic bubbles in the metal.

There may be numerous causes of cavitation such as incorrect matching of propeller style to application, incorrect pitch, physical damage to the blade edges, etc...

Be advised disturbances in the water flow forward of the propeller can result in blade damage which appears to be blade cavitation, but is actually due to non-favorable water flow.

09-05-2013, 11:53 PM
My boat does this with a perfect prop also. I attribute this to the angle of the rudder to the prop.

190 Skier
09-06-2013, 02:28 PM
My boat had this occur last year as well, only on a tighter turn. It was the tranny slipping not the prop cavitating. Had it rebuilt and found the clutches were well worn. Not an issue since the rebuild.