thinking about trimming some of the diffuser ring off my 32P labbed B1's , just want to bring up the RPM just a hair, I'm looking for real world results how this affects fountain hulls specifically, not worried about planning,.... no issues there , any thoughts on this ? the general consensus on this is that it may decrease stern lift , is this something that will hurt the performance on a Fountain

According to Merc Racing taking it back on a Maximus will settle the stern and increase speed by 2 - 4. I'm sure the other prop wizard would have his own take on this as well.

My thought, friend did it to a set, would be few, 2 -3, hundred and would likely drop the stern some. You can cut it off a little at a time or just wack it off then weld it back if it flops.


Little add here, my friend did take the diffuser off a set of props on his single step 35, note here he was 100+ when he did this, and did gain a few hundred, do not remember him making any negative remarks about handling. I would assume the effects would be less on your 42 than n a 35. I have always felt that a pad bottom boat likes to run on it's tail at speed, to settle the tail is not a bad thing in my mind.