1988 force 125 lower unit

[jimbowie85]

I have a force 125 1988 lower unit siezed up. can anyone tell me what year and hp models will interchange with my motor. model #1253X8C ser. # 1094.

 

[Frank Acampora]

Re: 1988 force 125 lower unit

Almost any one piece lower unit from late Chrysler up tp 88 Force three or four cylinder engine will fit; they never changed the drive shaft, gearcase, or internals. Everything just bolts right up. The only changes were the shape of the skeg. If you use a lower unit from an 85 Horse Force, check it by spinning the drive shaft and see how many turns it takes to turn the prop shaft one turn. On most, the gear ratio is 2-1 rather than the 1.78 to 1 of your lower unit. You will need to use a prop with about 2 in pitch more. The upside is that you will gain about 2 MPH. The downside is that you will use more gas at WOT.

 

[jimbowie85]

Re: 1988 force 125 lower unit

Almost any one piece lower unit from late Chrysler up tp 88 Force three or four cylinder engine will fit; they never changed the drive shaft, gearcase, or internals. Everything just bolts right up. The only changes were the shape of the skeg. If you use a lower unit from an 85 Horse Force, check it by spinning the drive shaft and see how many turns it takes to turn the prop shaft one turn. On most, the gear ratio is 2-1 rather than the 1.78 to 1 of your lower unit. You will need to use a prop with about 2 in pitch more. The upside is that you will gain about 2 MPH. The downside is that you will use more gas at WOT.

thanks frank . so nothing after 1988 will work? also im new to boating what is WOT?

 

[Frank Acampora]

Re: 1988 force 125 lower unit

I'm not sure! My experience is with engines up to 1990. I know the older lower units will bolt up to the 1990 engines, however, I'm not sure it will work the other way. So I gave you a conservative answer. Later units may bolt up, but at some year, Merc started changing lower units.

 

[Scaaty]

Re: 1988 force 125 lower unit

WOT is wide open throttle