87 and 89 Force 125 Lower Unit Compatible?

[sparkdogg77]

Hey Guys,

I need a new lower unit for engine 1254X9B. I found a lower unit from engine 1254X7B.

Will the lower unit fit without any modifications?

The major difference I see in the pictures is my '89 has a 2-piece shaft and the '87 has a 1-peice shaft. Since they both should be 20", I figure they will work but I wanted to check with someone who knows something about these Force motors before spending the money.

Thanks,
Tommy

 

[SkiDad]

yes it should work fine - the water pump will be a different style but as long as you keep that in mind when changing the impeller. See Frank's post: http://forums.iboats.com/forum/engi...tboards/624116-swapping-lower-units-one-piece

 

[Frank Acampora]

I don't remember exactly, but when they went with the Merc. water pump in 89, the pump itself is larger. You may need to cut out a small piece of aluminum from each side of the web in the midleg for pump clearance. If you do need to, you can burr it out with a Dremel and coarse bit . I get in there with a recip. saw. Fast and dirty.

 

[sparkdogg77]

I should have bought the one I asked about in this post since I had a model number to go by but for $100 less, I found one from a 1988 that looked better, still had the skeg and was told that it was a 20 inch shaft but when it arrived, it was a 25 inch shaft. My question now is, should I return the lower unit ($290) or should I try to convert it to a 20 inch shaft (using 1989 lower unit)? Is it even possible, or would I have to find a 20" shaft from pre 1989?

 

[pnwboat]

I would return the lower unit. Not worth the effort to convert a 25" shaft to a 20" shaft. Too many things to take into consideration, bearing clearances, shims etc etc. special alignment and installation tools most of which are no longer available. Better off to get a whole unit already assembled. That's just my opinion though.