Recent haul out for bottom paint on my H376, we had them inspect for vibration above 2500 rpm. Cutlass bearing was the verdict. Hmmmm. That's the 3rd Cutlass in 15 yrs. I had my diver pull the OEM 2 blade prop and have it tuned. Turns out the 2 blade was really out of whack. Total cost for diver and prop retune was only $300. Now WHY didn't I think of that sooner?? And yes it made a huge difference in vibration and thrust.