Force 125/85

JoeCrow

Petty Officer 1st Class
Joined
Nov 1, 2007
Messages
218
I have a Force 125, I know it's a 125 as it has 4 cylinders
The serial number on the mid section comes back to an 85hp
I also know the lower units are interchangeable
I read somewhere that the 85 lower end had a different gear ratio
Was it ever a common practice to change out the lower units for more top end?
I replaced the motor with a new Merc and am selling the Force,
I just wanted to know what was going on, cause I know I'll get asked
Anyone looking for a good running Force?
It's a 20' shaft, I have a 25" transom, hence the change
Thanks
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: Force 125/85

Yeah! I change them all the time. Gives about 3-5 MPH more. The 125 always had a 1.78 to 1 ratio. Some of the 85s and all the 90s had 2 to 1 ratio.
Put a 2 to 1 on a 125 and go up 2 pitches on the prop and you still get 3-5 MPH more at the same RPM. Don't ask me why it works, it just does.

At any rate, the midleg, shroud, hood, and lower units are all interchangeable. However, if you have a model plate that says 85, then it is most likely that the engine was lunched and a 4 cylinder was mounted to replace the three without changing anything else.

Where are you located?
 

JoeCrow

Petty Officer 1st Class
Joined
Nov 1, 2007
Messages
218
Re: Force 125/85

Thanks for the info,
that explains a lot....
I think the change was vice versa though
and that's how I ended up with a 20" motor on a 25" transom
The boat is also rated at 125
I'm in Jersey not far from Philadelphia
Thanks again
 
Top