90 hp force lower unit reassembly

[jeremydial1981]

I have a 1991 90hp force. I have just replaced the water pump and I am attempting to reinstall the lower unit but (not for lack of trying) I just cant get the lower unit to seat into place. I have turned the flywheel, I have turned the propeller I have turned and twisted (all gently of course) and I am starting to think it is just screwing with me. Can it really be this difficult or am I doing something wrong.

 

[jerryjerry05]

Re: 90 hp force lower unit reassembly

The motors just jerking your chain.REAL HARD!!!
Kidding,look up inside to see if the old rubber boot is blocking the hole.
Sometimes they can be a BUGGER!!
Had a guy call and ask the same question.Said he was working on it for 2 hours and no luck.
He said I could have another motor if I could get it on.
30 seconds later I was tightening the bolts.
Just keep trying!!!

 

[jeremydial1981]

Re: 90 hp force lower unit reassembly

The motors just jerking your chain.REAL HARD!!!
Kidding,look up inside to see if the old rubber boot is blocking the hole.
Sometimes they can be a BUGGER!!
Had a guy call and ask the same question.Said he was working on it for 2 hours and no luck.
He said I could have another motor if I could get it on.
30 seconds later I was tightening the bolts.
Just keep trying!!!

I don't think that's it as I have the rubber boot slid down on the drive shaft.

 

[pnwboat]

Re: 90 hp force lower unit reassembly

Just like Jerry said, just takes some patience. I've found that it's a little easier if the motor is tilted as far down as it is can go and still be able to maneuver the lower gear case around.

 

[Frank Acampora]

Re: 90 hp force lower unit reassembly

First, slide on the steel collar and rubber boot. then, (I like to have the engine tilted all the way up so I can stand and see what I am doing) keeping the drive shaft parallel to the front of the midleg, slide it up. Engage the water tube into the pump adapter and "Feel" for the hole in the crankshaft. Some go right in and some like to fight you. After the splines mate, you still will need to locate the shift rod in the hole so they can be driven home. Look at the parting line of the case. It needs to be the same on each side and front to back. This is how you can tell that the shaft is pointed at the crank.

The main thing though is to keep the shaft pointed at where you think the center of the crank is then gradually move it until it enters the taper. Then, you can turn the shaft and engage the splines.

Now, because you don't have a bolt handy, as you reach for one, the lower unit slides out and you begin the process all over again. Finally, after saying the correct swear words and mumbling under your breath about the engine's religion, parentage, sex life, and illegitemacy, it will relent and let you assemble it.