115 Impeller replacement

[dyount]

1984 115ETLN.

I'm in the process of installing a water pump kit have yet to figure out how the impeller is supposed to come off. On top of the impeller there is a cap/cover over a nylon bushing followed by three washers. I would suppose there is a retainer in this assemly but I sure don't see it. None of this shows up in my Yamaha shop manual and I don't see this assembly in the exploded view parts list either.

Anybody know what I'm missing here?

Thanks....

[jb123]

you need to pry off the metal cover,i use 2 flat screwdrivers on each side, followed by the three rings then the split sided seat. then pull off impeller housing, keyway then impeller.

[Ken]

dyount,
Pretty much what jb said.
I take two large flat screwdrivers and use two small pieces of wood over the old impeller as pivot points and gently pry the metal retainer off the nylon bushing. This is after I remove the metal impeller cup.
There's a good chance the nylon bushing will crack on you - if so, replace it.
Remove the impeller - may have to pry it up also.
Then the woodruff key.
Good luck [img]smile.gif[/img] ,
Ken K

[jb123]

Ken...looking at the lower unit parts section for most of the newer outboards, there is the new 3 piece washer,collar and plastic that was referred to here. do these parts actually cram above the metal impeller housing and below the plastic housing ??? i know it shows that in the parts diagrams, but the metal has the locking pin/tab that turns up into the plastic housing...
where does the room for these parts come from....inside the center of the metal impeller cover???
I guess i have been installing mine wrong for the last 2 pairs of motors, for the last 6 or so years....and never an overheat problem.

[Ken]

jb,
I think the water pump assembly/parts may be a little different for your V-6, I only have a manual for my little 2000 C115, and it is the only water pump I have ever worked on.
dyount has got an '84 model 115, and I believe his water pump is the same as mine.
Take a look at this link to a pic that I took on the last pump repair (albeit out of focus ):

http://i82.photobucket.com/albums/j2...terpump012.jpg


This is what I had when I removed the metal impeller cup. The center of the metal cup is large enough so that the retaining ring, nylon spacer and three washers go thru it. All this fits between the metal cup and plastic impeller housing.
The pic shows the retaining ring and the nylon spacer just below it. The three washers, one "wave" and two regular, fit just below the nylon spacer. All this holds the impeller in place vertically, while the woodruff key has it locked horizontally on the drive shaft.
I hope this helps - let me know if the pic link comes up ok.
Ken K [img]smile.gif[/img]

[jb123]

looks correct and i have been doing it wrong all these years....thanks !

[Ken]

jb,
When you think about it, I really don't know what purpose the three washers, nylon spacer, and retaining ring perform, because the impeller is pretty well "trapped" and held in place by the metal cup, which is held in place by the plastic housing - go figure [img]smile.gif[/img] .
Maybe the design is a carry-over from previous years - dunno.
What gets me is that they use only one woodruff key off the drive shaft to drive the impeller - and with it being rubber, you would think that it would be distorted on one side .
Oh, well, it works pretty darn good, so I'm gonna fuggeddaboutit [img]smile.gif[/img] [img]smile.gif[/img] !
Ken K