I have an '89 Taswell 43 and have a noticable vibration when motoring above 2300 RPMs. It does not come from the engine or transmission, rather aft. I have a Max prop and recently had it rebuilt. I have also had the cutless bearing checked and it is within tolerances. If anything the vibration increased after having the max prop factory rebuilt. Does anyone else have this problem? Is it cavitation? My mechanic suggested possibly lengthing the shaft to allow more water above the prop tips, but this may cause other problems.