i just bought a 1996 26' billfisher i have the 200hp volvo diesel and 290 dp out drive with a-4 props ive have a bad cavitation problem, the power trim motor was bleeding out thought that might be the problem so i replaced it and i had my props rebalanced they said they wrere ok even that they are pretty old i have the big kd transducer thats mounted center of the keel but i think its up far enough that it wouldnt matter im thinking mabe the prop hubs are spun , the boat dont cavitate until i run for about 20 minutes , anybody have any input on this problem id appreciate it