Lower unit for Force 125

Leonard281

Recruit
Joined
Apr 23, 2009
Messages
5
I have a 1985 Force 125, the housing between the engine and lower unit was busted. I bought s used housing and installed, motor bolts up but lower unit doesn't. I do not know for sure the year model of the used housing. How do I determine which lower unit will work. Are the splines for lower unit different for each year model of engine?
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: Lower unit for Force 125

Mercury did not change the drive shaft splines until sometime in the 90s (94, I think) All three cylinder and four cylinder lower units will bolt up to any midleg from 1979 through at least 1990.

Are you sure you did not buy a Mercury midleg? this midleg has studs that pass through the lower unit and a different bolt pattern. The earlier Force lowers will not fit. The engine block, however, will bolt right to the match plate.

If you could, a couple of photos would be quite helpful.
 
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