There had been a rash of reports of the electric toilet going inop - and in my situation - and some others, the problem was a sheared or missing cotter pin holding the impeller on the shaft of the motor.
Here's the writeup I did at the time: I went down today and took the head apart and here is what I found:
As someone else reported this week, there are no metal blades installed
in the Wilcox-Crittenden Newport Electric Macerating toilet on my C350
(Hull #sixtyeight) - nor did it look like there had ever been any. Instead, I found
stiff plastic/rubber output impeller, spinning free on the motor
shaft. As someone pointed out, there should be (and probably was at
one time) a 3/32" x 1.5" cotter pin holding the impeller to the shaft.
That person also pointed out that there was enough room to squeeze a
1/8" x 1.5" pin through the impeller and shaft. I did that and the
head seems to work as I have come to expect it.
A couple of things I learned - besides the exact size of the cotter pin
needed for the repair. I used a very handy small wet/dry shop vac to remove any water (as
much water as possible) from the bowl before I began the task. A joker
valve in good condition should keep a flood of bad stuff from escaping
when you remove the pump.
1) The exploded parts list shown on the Wilcox-Crittenden website
(note - WC got sold a while ago and the mention of their website might be outdated) does
not represent the installation on my boat. As noted above, there are
no metal blades, nor the associated "jam nut" that was supposed to hold
them on - nor was there any indication that there ever had been any.
2) There are two brass colored bolts on the outside of the pump
chambers that are designed to hold replaceable zinc elements. WC told me at the time that the zincs were no longer used, nor required. Simply
remove the plastic cover and they should be readily visiblle.
3) One of the above noted brass colored bolts will need to be removed in
order to access one of the screws holding the pump and impellers to the
toilet base. Seems like poor design to me. A large bladed slot
screwdriver is needed to remove those bolts - and some teflon tape to
reinstall them.
4) The toilet was actually pretty easy to remove and get to the pump
parts. Three bolts undo the toilet from its mount (more on that below). Once the toilet bowl is unfastened from the base, you have enough room to unscrew the motor/pump assembly and remove it to access the impeller and shaft.
5) I used a very handy small wet/dry shop vac to remove any water (as
much water as possible) from the bowl before I began the task. A joker
valve in good condition should keep a flood of bad stuff from escaping
when you remove the pump.
6) There has been some writing and a posting on the 350 owners site
about the mounting of the toilet bowl to the boat structure. I found
mine to be quite solid. There is a sort of "three part gasket" between
the bowl base and the boat structure. The gasket consists of a piece
of metal of some sort, some high density foam or plastic material, and
another layer of metal. The first layer is bolted firm to the boat
structure. There are holes bored through the top layer and the middle
layer to access these screws holding the bottom plate to the structure.
There are also bolts that protrude up through the top layer that the
bowl is actually attached to. The purpose of the middle layer seems to
be insulation or sound deadening - isolating the bowl and pump
mechanism from the rest of the boat structure. Doesn't do a whole lot
as that toilet pump will wake the dead.
All in all, although it was annoying, and I found some things I hadn't
expected, it turned out to be a pretty easy repair and I learned a lot.
I'm hoping that the larger diameter cotter pin will be more robust and I won't have to repeat the repair anytime soon.
(Note that I originally wrote this in late 2003 and haven't had a problem since!!! knock on wood)
Good Luck!