Replacing force motor with newer Mercury- questions

[griggsmars]

After many on going problems with my 96 Force Mercury 120 hp outboard, I am considering replacing with a 2004 Mercury 115 hp outboard. I believe my Force motor to be a 20" shaft length, the Mercury I am looking at is a 25" shaft length. I measured from the top of my transom to the bottom of the center pontoon and it is about 24" My question is - what are the problems associated with having a motor that sits too deep ? I can try to shim it up a couple inches, but not sure what problems that might cause. My boat is a 30' pontoon, and most of the time we are just putting around, but sometimes have to get on the gas. Thank you in advance for any advice.

 

[jerryjerry05]

Pontoon, probably won't notice much difference.

The shifter might or might not work?
That depends on the shift linkage.
Your lower unit is it a 3 or 6 jaw reverse??
As I understand it, the 3 jaw is set up for the older Force shift and the 6 is for the Mercury linkage.

 

[griggsmars]

Jerry, In a previous forum you told me that I had a mercury lower unit. I'll attach a picture. Thank you

 

[jerryjerry05]

You can have a Mercury lower and still have the Force shifter.

Look up the difference between the 3 and 6 jaw gear cases??

I hope this prints??

https://www.boats.net/catalog/mercury/outboard-by-year/force-outboard/1996/0e138600-thru-0e202999-usa-120hp/gear-housing-identification

Or just take a pic of the bolt that holds the steering fin in place(from top down) and post it