When I purchased the boat the four bladed wheels were on there. They were 29 x 30 with a slight cup originally. After banging them up a bit, I decided to go with the spares in the lazarette. Those I imagine were the orginal 3 bladed 29 x 31. With a light load I was able to get 29 knots our of her and turn 2300 rpm but took a bit longer to get out of the hole.
I did not decide these values and have no Idea how they came up with them. I do know that the engines were de-tuned from 930Hp to 870Hp(Crank). So, I think we now have the same horsepower
If you are not getting any soot, then I guess I am still a little over propped with my four bladed props which I reduced to 29 x 29 and a little cup. My guess is that the props were set up for when the boat had the beefeer Injectors and the correction was never made.
If you wanna chat anytime, give me a call at 786 247 7274.
I still havent gotten the props just right, but I think if I go to 28 x 28 the problem will go away.