Re: [OMC-Boats] Possible impeller problem

From: BLDFW <bldfw@...>
Date: Fri, 22 May 2009 18:41:48 -0700 (PDT)

Thanks Andy,
I think my problem is the water pump/impeller in the outdrive.  It stopped pumping water up into the manifolds.  I'll take another look in the morning.  I'll run it and see if it pumps water again or if it's hosed for good.
Dallas, TX
1970 Evinrude Explorer - 155 Buick V6 - OMC sterndrive

--- On Fri, 5/22/09, ANDY PERAKES <aperakes@...> wrote:

From: ANDY PERAKES <aperakes@...>
Subject: Re: [OMC-Boats] Possible impeller problem
To: "Evinrude & Johnson Boats of the 1960's and 70's" <>
Date: Friday, May 22, 2009, 4:37 PM

#yiv1264377340 p {margin:0;}

There's any number of potential reasons, everything from "the mouse nest broke lose and plugged the port" to marginal parts finally giving up the fight.  I don't know what the others have experienced, but my '67 Reveler has two weak points:  about every 15 years I need to replace the alternator and water pump.  I've noticed the water pump retains a lot of "wet" inside and even though it has a brass impeller, the bearings, housings and seal seem to get "chunk rust" build-up.  I last changed my pump about 8 years ago and started pulling the hoses off the pump housing in hopes that it might help slow down the rate of degradation, but I'm still within the 15 year window so I don't yet know if it has helped.  I do know if you need a pump and/or gasket you will have one heck of a time finding one.  If I remember right, I paid $380 for my last pump, then later bought a spare for $190 that I luckily stumbled upon in a clearance sale.  I've heard some
 people talk about using the auto pump and just plugging the heater core hose, but I'd be very cautious with that route unless you know the flow rates and pressures are the same.  Also, the auto unit runs in engine coolant which has corrosion inhibitors and other stabilizers so it may be more apt to fail in an environment void of that protection.  As I recall, the mount interface is slightly different too so you'd need to make modifications that again expose you to more potential failure modes.  Before you pull your pump off the block (and likely destroy the gasket), I suggest you pull the hoses and look/feel around inside to the extent possible.  If you can feel the impeller is loose or see lots of garbage in there, that will be a pretty good indicator you need a new pump.  If it looks clean and tight, I'd probably look elsewhere first.  If needed, you can make your own gasket, a process that will be much easier if you can keep the bulk of the
 existing gasket in tact to use as a pattern.  Btw, I last replaced the alternator about 6 years ago and used one of the retrofits that has a built-in voltage regulator.  So far it runs fine and I have not experienced any trouble with it.

----- Original Message -----
From: "BLDFW" <bldfw@...>
To: omc-boats@...
Sent: Friday, May 22, 2009 4:04:50 PM GMT -05:00 US/Canada Eastern
Subject: [OMC-Boats] Possible impeller problem

I got my new exhaust hose installed and cranked her up again.  I let it run about 10mins monitoring it closely.  When I first started it I pulled the hose off the rear manifold where the water is pumped up from the outdrive in a good steady flow.  I watched the temp gauge (160d thermo) but did not see any discernable shift. 
I closed the engine compartment just to hear how she idled with it closed.  When I reopened the air felt a bit warmer than I would have thought after running only 10mins or so.  I started feeling hoses and the hose on the right side from the outdrive was hot while the hose on the left side was mildly warm.  Of the hoses in the front, two were getting hot and the other two warm but not really hot.  I pulled the right side hose from the outdrive to the manifold again and this time no water pumping.  Duing this time, the temp gauge had only gotten to about 115-125.
Why would it pump at first and then not pump after a few mins?  Seem to work fine yesterday.  I will have to pull the water pump for sure. 
Thoughts, insights, lessons learned?
Dallas, TX
1970 Evinrude Explorer - 155 Buick V6 - OMC sterndrive
_______________________________________________ OMC-Boats mailing list OMC-Boats@...
-----Inline Attachment Follows-----

OMC-Boats mailing list
Received on Friday, 22 May 2009

This archive was generated by hypermail 2.2.0 : Tuesday, 29 July 2014 EDT