1991 Force 120 HP Lower Unit

mrbongo

Cadet
Joined
Aug 29, 2011
Messages
7
I have another string going about my fun with this outboard. Lower unit was cracked and I didn't see it. I don't know if that can happen
from running it dry?

Can I use a 1990 20" shaft lower unit to replace? This one is a long shaft. 25" JUst found a used one close by but it's a 90 HP short shaft. 1990.

????
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,183
Re: 1991 Force 120 HP Lower Unit

If you have a 25 you need a 25.
If your gonna take it apart and swap pieces.Then you need shim tools to assemble it.
Cracks usually happen from freezing.Or the guts came apart and are forced out??
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: 1991 Force 120 HP Lower Unit

I THINK from 1990 to 1994 they were all two piece drive shafts. SO: If the 1990 is a two piece drive shaft and your lower is original (two piece also) you can use your upper drive shaft with that lower and it will be fine.
 

mrbongo

Cadet
Joined
Aug 29, 2011
Messages
7
Re: 1991 Force 120 HP Lower Unit

Thanks for all the help. I'll probably go out and look at it. He sent a picture but it's still attached to the upper part of the outboard. Can you tell if
it's a two piece shaft without removing the lower unit from the motor?
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,183
Re: 1991 Force 120 HP Lower Unit

No.The 120 from 90-94 are all supposed to be the same.Two different drive shafts.So your drive shaft will change it to a 25,I was thinking one piece shaft.J
 
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