Fellow board members, I tried this post on the Scarab forum already with no responses, figured I might get a better response here.

Would like to know if there are any fellow Scarab 31 owners on the board who have tried 4 blade props on their rigs. Currently switching to XZ drives so I have to get new props anyway. Was running old 23" solid hub Mirages. Drives seem to be pretty deep to me so I'm thinking 4 blades might create too much stern lift.

My neighbor's 33' Scarab has a set of 26 pitch Bravo One four blade props. His boat came with them and I haven't heard him complain about the props.

i ran the herbot, hogs breath boat for a while. it seemed to like hydromotive four blades really nicley. make sure they are turned out. you will have better control.

Treadwell

I have 30 Scarab. My experience has been that at the same x-dimension, the 4-blades will give you better mid range speed and hole shot but reduced top end. To get the best of everything, I suggest you consider raising the x-dimension by using the Merc Sportmaster or IMCO 2" shorter lower units with the four blades and all your statistics should improve.
I set my base line up so that I struggled to get on plane with Mirage 3-blades and the IMCO lower units. From that point, I raised my drives a total of 3" ( 1" at a time ). The boat got on plane easily at + 2" in x-dimension with the Bravo 1's. At +2" in x-dimension I added 4 mph turning the props out, and 6 mph turning them in. The boat is significantly more stable with the Bravo 1's vs. the Mirages. If your budget allows, I would go +3" in " x " and use spacers to come back down if you don't like the results.