Throttle 2575rl
- Thread starter Cowboy03
- Start date
BigKahuna
Well-Known Member
I had a 4.3L V6 Mercruiser with 220 HP and it pushed my heavy R to 42mph. Your 5.0 Volvo has 270 HP but your 25 footer is probably even heavier than my 22 footer. I would think at least 42-45.
BigKahuna
Well-Known Member
28? Are the toons clean? I had a stainless Mercury Mirage plus 17P on it. It had a really good hole shot and top end was 42 at 4500 rpm's with my wife and I and the Bimini was always up. Your 270 HP boat should do alot better than than 28.
Vikingstaff
Moderator
Propping can be tricky. I am not experienced with inboard motors. I don’t think going up in prop size is your issue. Thoughts:
(1) Being around a 17p sounds pretty good. Maybe type of prop and diameter could be dialed in…maybe not. What specific brand of prop and both diameter and pitch is it now?
(2) What Bennington boat model, length, and hull do you have? These are all super important as boat layout, weight and pontoon hull all impact potential performance. These are impact additional information pieces along with specific prop information.
(3) Main concern I am considering is what Daril mentioned. How dirty are your pontoons? When people have that compromised of perforance, it is often due to scum and algae build up on the pontoons. It slows performance significantly, even with a little bit of it.
(4) Another possibility with such compromised performance for that motor is water in the pontoons. Does your list to one side at all, or any evidence of a small pontoon leak letting water into 1 of your pontoons? That can add some extra weight very quickly and compromise performance greatly.
(5) What are the max RPM’s for your motor? What is it running at RPM wise when you are at WOT, with a light load? That two will help dial in issue if part of the problem is prop.
All of this said, to be at only 28 MPH at WOT now, the main thought for me is not prop, it is something else. I don’t know what that something else is, but answers to some of the above can help all of us dial in our advice. Without more information it sounds more like dirty pontoons or water in a pontoon to compromise performance that much since you have a 17p prop now….
(1) Being around a 17p sounds pretty good. Maybe type of prop and diameter could be dialed in…maybe not. What specific brand of prop and both diameter and pitch is it now?
(2) What Bennington boat model, length, and hull do you have? These are all super important as boat layout, weight and pontoon hull all impact potential performance. These are impact additional information pieces along with specific prop information.
(3) Main concern I am considering is what Daril mentioned. How dirty are your pontoons? When people have that compromised of perforance, it is often due to scum and algae build up on the pontoons. It slows performance significantly, even with a little bit of it.
(4) Another possibility with such compromised performance for that motor is water in the pontoons. Does your list to one side at all, or any evidence of a small pontoon leak letting water into 1 of your pontoons? That can add some extra weight very quickly and compromise performance greatly.
(5) What are the max RPM’s for your motor? What is it running at RPM wise when you are at WOT, with a light load? That two will help dial in issue if part of the problem is prop.
All of this said, to be at only 28 MPH at WOT now, the main thought for me is not prop, it is something else. I don’t know what that something else is, but answers to some of the above can help all of us dial in our advice. Without more information it sounds more like dirty pontoons or water in a pontoon to compromise performance that much since you have a 17p prop now….
The Hillbilly Barge
Well-Known Member
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How accurate is the speedometer