Got my two props and threw on the 15" diameter 15 pitch 4 blade Solas. Ran to the mouth and back so I need some more testing to see how I like it. Playing more with the trim on the 19p that was on it I was able to hit 39.6 mph at 5100rpm. With the 15p 4 blade she's at 36.5 and 5900rpm. So I lost 3mph and gained 800rpm.. At 4400rpm I used to be a a little over 34 mph I'm now a little over 27mph. I think best fuel economy for a 150hp Yamaha 4 stroke is around 4000 rpm which is wear the 19 was at 28mph. Need to do more testing but thinking to get down to 4k with this prop I'll probably have to see how it planes around 25 ish.
Noticed punching it out of the hole the boat stands on end more, the bow comes up higher and you are blind for a few seconds. I was not expecting that but can work around it. Also, I did not have a lot of trim with the 3 blade 19p but I have even less now. I want to run this one for a bit and then I'll throw the 15"×15p 3 blade on and see how it is. I may end up having to run a 17p 3 blade but whatever it takes to dial it in.