My boat is in the water and I have a vibration port side (suspect cutlass bearing in the shaft). Twin Cummins 220's....does anyone know if there is a standard shaft size? 2", 2.5" ?
First I would take a quick look with a mask and wet-suit to make sure you just don't have something wrapped up on the prop. If all clear you will need to get hauled anyway and you can test cutlass bearing then.