85hp to 125hp

[smax]

I might be repowering my 16' bass boat and I was wondering what kind of speed increase I could expect? I am currently running a Force 85hp and I just picked up a Force 125hp. With the 85hp the boat runs 40ish pretty consistant. So what kind of gains do you think I could expect going to the 125hp?

 

[Frank Acampora]

Re: 85hp to 125hp



Powered with a 90 this boat did 55. powered with a 125 it topped out at 60.

It takes roughly four times the horsepower to double speed so with a roughly 32% more power you would expect 4-6 MPH more--assuming the 125 is healthy and correctly set-up and propped.

 

[smax]

Re: 85hp to 125hp

I was thinking 42-44mph maybe, so I guess I was probably close.

 

[RRitt]

Re: 85hp to 125hp

125 / 85 = 1.47 ==>> sqrt 1.47 = 1.21

40Mph * 1.21 = 48.5Mph

 

[smax]

Re: 85hp to 125hp

How difficult would it be to swap out the 1988 85hp power head with the 1986 125hp power head?

 

[Frank Acampora]

Re: 85hp to 125hp

Not difficult at all. Everything swaps and bolt pattern is the same.

 

[smax]

Re: 85hp to 125hp

Do you know if my 85hp cowling will fit over the 125hp power head, or will I need a taller cowling? The 85hp is the black cowling and the 125hp is the older white.

 

[Frank Acampora]

Re: 85hp to 125hp

The 85 is three cylinder and the 125 is four--one cylinder taller. Cowls will not swap. Additionally, white cowl and black cowls have a different shape. So while the engines can be switched easily on the transom an even the powerheads can be switched on the midlegs, external lower cowl and cover must be changed too.

 

[smax]

Re: 85hp to 125hp

That's what I needed to know. Thank you sir!