Water pump replacement '72 Evinrude , extra parts!

[handle]

Took lower unit apart over a year ago to replace the water pump. Everything seems to be going back together as it should, except for this O-ring that the diagram shows going on main shaft just above water pump housing. It does not seat any where correctly in or above the housing. Anyone have some advise for me before it becomes extra parts. Can't figure out where it goes.

 

[AlTn]

Re: Water pump replacement '72 Evinrude , extra parts!

what hp. motor...model no.?

 

[OutOfControl]

Re: Water pump replacement '72 Evinrude , extra parts!

handle, I assume you are referring to a 1972 Evinrude 25 HP longshaft #25253R that you posted about in another thread.
From a parts diagram on the BRP web-site it appears that their is an o-ring either embedded in the top of the water pump housing or on top of the impeller under the housing cover.
Hopefully someone with more intimate knowledge will chime in.
OutOfControl

 

[lindy46]

Re: Water pump replacement '72 Evinrude , extra parts!

Maybe the 0-ring that sits in the groove at the top of the driveshaft?

 

[emckelvy]

Re: Water pump replacement '72 Evinrude , extra parts!

That O-ring (part #11 in the diagram) above the water pump goes in the O-ring groove in the driveshaft, just below the splines which engage the crankshaft. This seals water out of the driveshaft/crankshaft splines.

OMC is just showing the 'stackup' of parts in the diagram, sometimes you'll see lines drawn thru a whole series of parts, which let you know how they're stacked-up.

You may or may not have had an O-ring on the shaft when you pulled the lower unit down; sometimes the O-ring stays in the crankshaft, other times a P.O. may have worked on it and neglected to install.

It might be a good idea to look up into the crank splines with a strong lite, to make sure it's free of stray O-rings and other debris.

Be sure to spread a thin layer of waterproof grease on the crank splines and O-ring before reinstalling the lower unit. Wipe off any grease on the very top of the driveshaft, otherwise you stand the chance of a 'hydraulic lock' and preload/damage to engine bearings.

HTH...........ed