Yamaha 90hp Lower Unit Dropping Help

[John from Madison CT]

Hello,<br /><br /> I have an 1990 Yamaha 90HP outboard. I wish to drop the lower unit and change the water pump. I am able to get all the bolts off BUT, I do not know what to do next.<br /> I have the aftermarket manual made by Selco, and it says that you need to disconnect the shift rod. First you put it in reverse then you undo a nut, just above the lower unit section, that holds the shift shaft connected to the shaft near the midsection of the whole leg.<br /> When you look at that part of the shift shaft, there is NO nut to disconnect, you only see shaft going into this mid section of the lower unit.<br /> Gee I hope that makes some sense. <br /><br />Has anyone hear done the water pump on a 3 cylinder Yamaha outboard and can offer some help?<br /><br />Thanks guys,<br /><br />John from Madison, CT

 

[12Footer]

Re: Yamaha 90hp Lower Unit Dropping Help

There is usually a nut where you decribed.<br />It is a very long one,with lock nuts on each side of it.It connects the 2 halves at the point where it exits the leg. If it aint there, something is amiss,and maybee was changed in later production models.But I don't know,just guessing on that one..<br />Also, if it is not there, have someone operate the shifter,while examining the linkage movement. It will give you a clue of the most "logical" place to seperate te two....The ol Spock approach.<br />

<br /><br />Good luck.

 

[John from Madison CT]

Re: Yamaha 90hp Lower Unit Dropping Help

12Footer,<br /><br /> I have 2 '89 Yamaha 90hp motors, and neither seems to have that nut you mention. In the Selco manual, they make it seem quite accesible but all I have is the ~1/4" gear shift shaft going down into the lower unit. <br /> I'm at a loss here and must be missing something . I just don't want to spend over $250 to have the water pump changed by someone else when I know what a darn easy job it can be.<br /><br /> Any more help would be great? Hey perhaps, the nut is accessible once you drop the unit an inch or so?<br /><br />John

 

[12Footer]

Re: Yamaha 90hp Lower Unit Dropping Help

Lower units get "stuck" at the splines of the driveshaft sometimes. Some gentle persuasion with a rubber mallet is usually enough to dislodge it. And you are probably correct in assuming the nut is internal.<br />On the only one I ever took appart, it was a split shaft,with an alltheread type of arangement outside the leg,port side. But that was 4 years back, and the engine was 40HP or so.