Which Oberdorfer?

Bolo

Member III
Although I've read most all of the threads about replacing a Sherwood pump with a Oberdorfer I'm still a bit confused as to which pump to buy. The N202M-16 (1/2" ports) or the N202M-15 (3/8" ports). Most of the threads on this site say the -16 for the Universal 25XP but when I look for the pump on the Defender site they recommend the N202M-15. The Catalina site recommends the N202M-16 for the 25XP. (Yikes!) To add to the confusion the hoses that come off the Sherwood on my boat are 5/8". I'm not near my boat which is almost two hours away but I'd like to order the replacement pump. Maybe I need to wait till I get on board and take some measurements?

IMG_1224.jpeg
 

Christian Williams

E381 - Los Angeles
Moderator
Blogs Author
I thought we had this figured out, but maybe not. Check the links below. My Sherwood was held on the M25 with funky spacers and needed a shaft extension to reach the engine armature, but the new Oberdorfer went right on without needing any of that, and I'm sure I reused the fittings (which needed a vice to get off the Sherwood).

I think I put the exact same pump on the E381 engine, in about 10 minutes. It may be that if you call a supplier, they'll know right away (there are probably few configurations of the basic pump).

 
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jtsai

Member II
Just installed two weeks ago, you can get the model # from the picture below; it is Defender Item #: 302315, 1/2 ports. The order took over 2 months. The input hose is 1/2", output is 7/8" and I have read others with different hose dimensions as you had noticed. Just need to find proper size bronze fittings or recycle the old. I elected new fittings saving the old Sherwood as a complete spare.
 

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Kenneth K

Contributing Partner
Blogs Author
As I recall, bronze pipe fittings only go as small as 1/2", so if you do the M-15, you have to install brass fittings. For that reason, I'd probably do the M-16 if it fits.
 

Bolo

Member III
OK so here is my confusion about the pump replacement. When I went on line to Defender they recommended and sent the N202M-908 pump to fit a Universal 25XP engine. They do not have the N202M-16 which has the 1/2" fittings that I think I need to accommodate the 5/8" hoses on the existing Sherwood. Here is the link for the pump they sent: https://www.defender.com/search.html?q=302315&x=0&y=0

And it looks like this...
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Notice the round plate at the back end.

Here is a shot of the back end that connects to the engine.
IMG_1327.jpeg

When I looked back on the past postings about this issue, mostly from Christian Williams, he shows the old Sherwood pump with a round connection end and the new Oberdorfer with a more "square" attachment plate. See images below.

two water pumps.jpgSherwood 4.jpgOberdorfer installed.jpg

So it seems to me that Defender sent me the wrong pump (even though it's recommended for the 25XP) or I ordered the wrong one. What I trully do need is a N202M-16 (which Defender doesn't carry) and not the purchased N202M-908. How can something so simple be so complicated?

I think that I can order the N202M-16 from Catalina Direct which has the square-ish mounting plate and that will fit my 25XP as it did with Christian's install on his boat. Got the RMA for the return from Defender this AM.
 

Kenneth K

Contributing Partner
Blogs Author
Try

pumpsandpartsonline.com

Haven't ordered pumps from them, but I did get parts.
 
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Bolo

Member III
Defender pump on it's way back, Catalina Direct pump ordered. Thanks for helping me clear this up guys! How can something so simple be so complicated at times? ;)
 

Tom Metzger

Sustaining Partner
FWIW: I put on the recommended (at that time) "-15" pump on my M-25XP in 2006 and was still able to sell the boat lat summer. No cooling problems.
 

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Geoff W.

Makes Up For It With Enthusiasm
Blogs Author
Defender pump on it's way back, Catalina Direct pump ordered. Thanks for helping me clear this up guys! How can something so simple be so complicated at times? ;)
Did the new pump come with an impeller? I am going to replace mine this year as well. And to confirm, did you get the 1/2” version from Catalina Direct?
 
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