Re: Mercury Mark 6 Water pump Woes

[Buccaneer]

Had the water pump apart four times today, comparing any differences
between the "parts" unit and the one resurrected, and tested in the
bucket each time. Success on the last time.
Noticed that on the mid section of the lower unit (that looks like a shoe)
where the water pump goes, there’s a 1/16" difference in the depth
of the step machined where the water pump discharge cap sits it.
This makes more room for the discharge cap with the spring tension
clips, to sandwich between the upper leg of the lower unit.
Not sure if this was a change "mid-year" as both units are 1956, or
a factory goof? The tension clip is a double layer clip. Tried adding
one layer on the good Mark 6 discharge cap, but it still wouldn’t pump,
even though it appears that the cap would be seated well on the pump housing.
Then planned down the bottom of the discharge cap a hair to get the ridges
out of it, and added the the other layer of the tension clip. For some
reason it all the lower unit pieced mated flush, and it pumped!
BTW, my old 1/2" drill turns 500 RPMS, and that was fast enough.
I added another foot height to the discharge tube with plastic tubing
to make sure it was capable of pumping higher thru the power head.
Will wait until the new OEM Merc impeller arrives before I put the lower unit
back on. There’s hope!

Prepare to be boarded!