Prop vibration

[Captain Ralph]

Brett, the shaft is new, cutlass bearings new, coupling matched. Vibration is most noticeable standing in the cockpit above the strut. To me it has to be the prop. They balance them at 550 RPM but spinning in air, not water. I bet it has something to do with a blade shape as these started out 28" square and are now at the extreme limit of pitch reduction. Props get swapped next Thursday and then I'll run it and see.

Looking so forward to your and Brett's updates.
Sadly, I was a victim of the folks that kept telling me my shafts were good. 3 sets of props latter; I replaced my suspect shaft and all vibrations went aweigh November 2022.
F M
Seems the cold shaft in the air (on the hill) measured real good. Apply some H P to it and it cork-screwed.
Moral,, trust nobody or nothing new or high tech. You feel a vibration, there it is..

https://www.youtube.com/watch?v=fgWLIvGZFGA

[cww]

We just sunk a ton of money into the boat. After some time goes by and we hopefully don't spend so much I am going to upgrade to 4 blades. I would now but just tapped out of $ and also out of time to get ready for our Bahamas trip. No time to be tweaking props.

Go with the Michigan DQX’s, I couldn’t be happier with them. Sizing is really easy, same diameter you have now but 1” less pitch to account for the extra blade area. The boat will perform better under all conditions and it also reduced vibration on my boat.