Force 120 lower unit question?

[JesseB]

I have a 1990 force 120hp and my lower unit has siezed. i have found one from an "88" but the gear housing is slightly different. Also I believe that mine is an L drive. My question is are these lower units interchangable? The shaft looks to be a match an the shift lever looks right but I'm not sure if there are other variables to consider. Thanks

 

[JesseB]

Re: Force 120 lower unit question?

Ok, it is not an l drive. i just researched it through this forum and I do not believe it is an L drive. But just to make sure, the L drive is on the in/out board motors, Correct? My motor is outboard.

 

[jerryjerry05]

Re: Force 120 lower unit question?

If the shaft is the same length it will work.Measure them and compare.Make sure waterpump fittings line up.Jerry

 

[Frank Acampora]

Re: Force 120 lower unit question?

I have a 1990 90 horsepower which has the same midleg as your 120. I have replaced the lower unit with an earlier unknown year lower unit. You can buy any lower from 1982 Chrysler to 1990 Force. --Any three or four cylinder except 70 horse Force.

Although the 1990 has a different water pump and a two piece drive shaft, all earlier units will bolt up to it with no problem. But you need a complete lower with pump included. Pump outlets are the same. Crank splines are the same and drive shaft length is the same AS LONG AS you are replacing a 20 inch long shaft engine with a 20 inch lower unit or 25 extra long to 25 inch.

If you really want to wake up your 120, see if you can find a lower unit off a 90 horse. It has 2 to 1 gears. If you do find one and you re-prop 2 pitches higher, RPM will remain about the same and speed will increase about 3-5 MPH