Low RPM Vibration

Danishgod

I have a 2014 Captiva 236 with a Bravo 3 and a 350 Merc MPI.  I switched the factory Mercruiser 24 pitch 4 X 3 prop set out as it was going to 5600 in WOT, way above the recommended range.  I installed Hill marine 26 pitch 4 X 4 prop set 26 pitch and discovered the following - RPM at WOT is now 5000 - this is good, but the speed did not move up at all.  The time to plane is about the same.  I am not particularly fussed about this so far other than when I move the throttle forward, there is a short RPM band where there is a noticeable vibration in the boat. 
Does anyone have any insights into this matter?

Handymans342

Could be Drive/engine alignment

randy56

Props new, could be bent, thats all that you changed.

212rowboat

i have a ron hill marine prop.. it's flawless.  
there has been a lot of talk about ron hill marine props here lately, and singing their praises. 
i have a buddy and he ordered a ron hill marine prop after trying mine on his boat and it performing very well- and his is a visibly out of balance, shoddily made PoS...
when they're good they're outstanding.  
when they aren't, they are terrible. 
they cost too much to consider rolling the dice by my reckoning, and i hate it- because when they're good they're very good. 

that said....... check your fasteners.