Force 125 Propeller spins but the boat doesn't move

[Zack Of All Trades]

A little bit of a backstory, I have been having issues with lower unit with my Force 125 the motor is pretty good but the lower unit had issues going into forward. upon taking apart the lower unit I found the following problems:
1. Bad seals, Water in the lower unit.
2. Worn Clutch on the forward side.

I took a lower unit off of my Force 85hp and installed it. at home tested it and the propeller spins in both gears in different directions as expected.

After I took it to the water the boat wouldn't move as if the spin isn't enough.

What could be the problem?
attached is a video of the prop spinning.

 

[Zack Of All Trades]

Edit: I noticed when off the power It doesn't actually engage I tried the adjustment based on the information from the book and I think the shift cable is bad because it bends when shifting. is this a correct assessment?

 

[jerryjerry05]

If the shift cable bends when shifting that sounds like the shift linkage is binding????
The seal where the shift shaft enters the lower unit can get clogged, causing the shift shaft to lock and not move and cause the problem with the cable.
Unhook the cable and operate the shifter by hand.
You will need to turn the prop by hand as you shift or you can break/bend the mechanism.
Post the results??

 

[Zack Of All Trades]

If the shift cable bends when shifting that sounds like the shift linkage is binding????
The seal where the shift shaft enters the lower unit can get clogged, causing the shift shaft to lock and not move and cause the problem with the cable.
Unhook the cable and operate the shifter by hand.
You will need to turn the prop by hand as you shift or you can break/bend the mechanism.
Post the results??

when shifting by hand it works, but when using the cable the cable bends.
Also FYI when I was using the older lower unit I didn't have shift problems with this cable until I swaped for this unit, it seems like its a bit hard to shift.

 

[racerone]

Take lower unit apart to see where it is binding.

 

[Zack Of All Trades]

Take lower unit apart to see where it is binding.

Where would it typically bind?

 

[jerryjerry05]

Can bind right where the shift shaft enters the lower unit.