Oberdorfer pump

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Ralph Masters

Quick question for Stu or Ron, When looking at the front of the raw water pump on a 25xp engine which way does the impeller rotate. Clock wise or counter clock wise??

Ralph
Ralph Masters
Ciao Bella
San Diego
Hull 367, 1987

KWKloeber

Quote from: Ralph Masters on May 20, 2015, 06:35:36 AM
Quick question for Stu or Ron, When looking at the front of the raw water pump on a 25xp engine which way does the impeller rotate. Clock wise or counter clock wise??

Ralph

CCW. With the pump installed (7-o'clock-ish), the inzie from your thru hull is the BOTTOM port, the outzie to the Hx, the TOP port.

kk
Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain

KWKloeber

Oh, and when replacing the pump or the impeller, read my post on TechWiki about the cir-clip on the shaft and why it's on there.

kk
Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain

crieders

And stay away from Oberdorfer
Stay with Sherwood
Cliff Rieders, c34 tall rig, 1990, hull #1022

Ron Hill

Ralph : It doesn't make any difference which way you have the blades facing when replacing an impeller.
After the first revolution all the blades will be in their correct position!!

Just use some liquid detergent to lube the inside of the pump cavity and the impeller blades.

A thought
Ron, Apache #788

Stu Jackson

Quote from: crieders on May 20, 2015, 01:52:15 PM
And stay away from Oberdorfer
Stay with Sherwood

WADR, absolutely backwards.
Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

Ralph Masters

Ron,
That was my guess, just stick it in.  I'm rebuilding an old pump, putting the new seals in tomorrow and putting the rest back together.
I'm not sure how old this pump was but I tried the little tool you show and I could not get it to move.
I ended up putting a carrige bolt down in it and drove the old seal out using that and a BFH.
Cleaning up the casing with CLR to get the green stuff out and reassemble tomorrow.
The one I got from a reputable guy on this web site has been working perfectly now for about 3 months, thanks Ron.
Ralph Masters
Ciao Bella
San Diego
Hull 367, 1987

KWKloeber

Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain

Stu Jackson

Further to Ken's link, here's a discussion of the shafts between the older & newer pumps.


http://c34.org/bbs/index.php/topic,6766.msg45766.html#msg45766
Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

KWKloeber

Quote from: Stu Jackson on May 21, 2015, 09:20:41 AM
Further to Ken's link, here's a discussion of the shafts between the older & newer pumps.


<<<In some of the OLD literature for M25 engines, there was a discussion that said, essentially, "If you pull out the shaft, you WILL have to remove the pump to reinsert the shaft."

That was because there was a female end on the shaft and a male end on the engine side.

The "newer" (mine's a 1986) Oberdorfer pumps have male end on the shaft and a female end on the engine side. >>>



http://c34.org/bbs/index.php/topic,6766.msg45766.html#msg45766

Stu,

I have to take issue with/correct the statement about "old" and "new" pumps having different shafts. 

My '84 M-25 had a female shaft pump, and another M-25 a year older had the male shaft.  It not a matter of the age of the pump or engine, it's which Ob pump that Universal/Westerbeke had and installed on any particular engine.  Two engines on the line in the same year (or month even) -- one could have had a female shaft, and the other a male shaft.   In fact, I still have my adapter plate and shaft adapter -- and I could buy a brand new Ob 202M-07 pump, and it would fit my M25 and have a female shaft.

ken
Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain

Stu Jackson

Yeah, we're splitting hairs.   :D  I think we all understand the way the engines were made, thanks to your excellent wiki article, and that some "newer" engines could have the "older" shafts.  In the larger scheme of things, the "old style" shafts eventually stopped being installed in the C34s.  IIRC, from Ron's many reports, it was only a handful of the earlier hulls.  The purpose of my linked report was, as part of the pump rebuild photos, was to show how the two parts - shaft and insid engine - mated.  Thanks for the clarifications.
Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

Ron Hill

Ralph : Good for you on the carriage bolt!! 
I just made my tool so I made sure that the wall of the pump housing didn't get scratched.
 
You can use any object even a screwdriver just as long as you don't scratch or scar the inside wall!! 
Ron, Apache #788