mercury 9.9 removing lower unit

[addicrous]

I have a 1999 9.9hp mercury long shaft outboard motor. I am trying to replace the water pump, but I cannot figure out how I remove the lower unit. I have unbolted it, but it hangs up on the shift shaft. My manual says to remove the shift shaft retaining clip next to the carbeurator, but I don't see what I am supposed to remove. There is a square bolt with a screw hole in the middle that looks like it connects the shift linkage to the lower unit. The shift linkage is visible, but I cannot figure out how to remove the shift shaft so that I can drop the lower unit. I have this motor partially disassembled now and I would greatly appreciate any help or advice. Thanks, Luke

 

[Downrigger]

Re: mercury 9.9 removing lower unit

It must be the same as my 15hp. Turn the thrittle fully to reverse. Once you drop the lower unit till it stops, remover the bolts holding the water pump to the lower unit and gently pull down on the LU until the pump separates. Once the pump separates you can lower the LU down off the driveshaft and out of the way leaving the upper part of the pump and the drive shaft hanging there by the coupling of the shift shaft which is under the pump. TAKE NOTE OF THE DIRECTION THE SHIFT CAM IS FACING BEFORE REMOVING THE LOWER PART OF THE SHAFT. Unscrew the lower part of the shift shaft counting the number of turns to remove (that is the shift adjustment). Once the lower portion of the shaft and coupling are out of the way the pump and drive shaft can be removed.

Why in the hell they put that coupling under the pump so you can't pull the unit without the above procedure boggles the mind especially when the shop manual has no mention of it. I think it's a long shaft thing.

Get help to put it back together (2 friends). You don't have enough hands to do that many steps at once. 1) Line up the splines top and bottom. 2) Line up the water tube. 3) Screw on the shift shaft and put together the pump while holding everything in place. 4) Line up the shift cam in the hole it must slide into at the bottom of the LU (before assembly shift the throttle fully to the forward position extending the shift shaft so it lines up in the lower unit first). It took 3 of us 4 tries to get it back together. A genuine pain in the arse.

Larry

 

[addicrous]

Re: mercury 9.9 removing lower unit

Thanks for the help. I changed the water pump. It is kind of a silly design.

 

[Whisper]

Re: mercury 9.9 removing lower unit

Thanks Larry- your post was a big help to me- one additional detail I would add is to remove the little c clip on the shift rod under the pump to allow the pump to slide down.
This is the first new impeller my 1994 9.9 long shaft has had and I think it will be the last after doing it this time. I think I'll leave the next one for my heirs to worry about!
By the way the old impeller looked pretty good after spending 13 years running in salt water- It makes me question the need for bi-annual replacement.

 

[superdow]

Re: mercury 9.9 removing lower unit

I had same problem with my 9.9 1986 mercury 2 stroke. There is a "shift shaft retainer" under the cowling which can be easily removed with a pair of needle nose pliers. Follow the shift shaft up into the cowling. It is held in place by the retainer assemply.

here is a video I found on you tube.

http://www.youtube.com/watch?v=Xv_8kTaNkAY