duo prop question

[R.N.]

Hi ,
I have a 24 ft bowrider with 5.7 gs Volvo Penta engine 4 barrel carb .
Now I have a set of F5 props and at WOT I can get the engine at 5000 rpm , which is a bit out of spec as max rpm should be 4200-4600.
The top speed at that WOT is 50 mph .
My question is which props will bring the WOT in the right range ?
Is the new prop increase the max speed as well?
Thank you

 

[Maclin]

I am seeing 4600-4800 as top RPM range for the 5.7GS in the Volvo Prop Guide, so at 5k you are not too far over. In my opinion the next step up, F6, should bring the top RPM in line. Top speed should be about the same.

 

[R.N.]

Thanks .
So do you see any issue with the F5 that I have if I keep away from WOT and do not past 4800 rpm?
I would say no as the engine is still have some extra power reserve but maybe there are things I do not know .

 

[Maclin]

I ran B5's (aluminum) due to being on a smaller lake and not needing to hit 50+, this was in a 22 foot Cuddy with 5.7 275hp, could hit 48+. I had run B7's before, but the way we used the boat those were a little too much prop. I really preferred the responsiveness of the lower B5 compared to B7. Also we almost always had 7 or 8 people with kids and all and mostly tubed. Just watch the RPM's and you will be fine. Those F5's will allow you to come out of the hole very well even with full loads. Only being 200 rpm over will not be an issue for very short periods.