Water Pump Question

Oct 3, 2011
825
Anam Cara Catalina 310 Hull #155 155 Lake Erie/Catawba Island
I have been following the OBERDORFER pump discussion (s) and have decided to go with one as compared to replacing our impeller again on our Sherwood.
We have 400 engine hours currently and will wait to replace the pump when it starts to go, I know no one has a crystal ball.
The question is about how many engine hours does the Sherwood last or when I replace my impeller next should I just do it all? We are in freshwater and have the M25XPB engine. About how long does the pump change over take and I can do that in the water as long as I close the sea cock? Much Thanks.
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
Our Sherwood went at 300 hrs. So you are doing better then us.

Which pump are you going to use? There is a straight drop in for $480 or there is one that requires the base to be modified for about $200. I did the latter. It took about 2 hours. But part of that was on two days because I painted it before I put it on. The direct replacement can be done in 10 minutes. And yes this can be done in water if you close the valve.

Good luck
 
Feb 26, 2004
22,759
Catalina 34 224 Maple Bay, BC, Canada
The question is about how many engine hours does the Sherwood last or when I replace my impeller next should I just do it all?
Alan, I strongly urge you to do this asap.

Think of it as a safety issue. Really. Pump craps out when you're trying to miss something, like a shoal or a ship!!! Engine overheats can be costly, too.

From the link below:

Also, unless you are persnickety about maintaining the engine and sea water pump, the Sw is the worst option of the two. It's prone to the shaft seizing (the pump is IRON not bronze like the Ob,) and if it seizes, it can break the fork off the camshaft.

Good luck.

The Sherwood pump is a POC. Here's why:

 
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KZW

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May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
Stu, come on man, don't hold back; tell us what you really think!!!

I bought my boat two years ago. The engine had 300 hours on it. The Sherwood was leaking, a lot! I replaced it with an Oferdorfer and am very, very glad I did. See the post in further back in this forum and in Mainsheet.

Follow Stu's advice. You will be glad you did!
 
Mar 27, 2016
26
Catalina 310 NAS Pensacola
I just did the Oberdorfer switch yesterday after SW seized. Piece of cake with a 3/8" wrench and a 90 degree and straight brass fittings ordered online (you can use the ones off the SW but one has to be ground down a bit for clearance). Close seacock. Works beautifully, about an hour's work.
 

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Nov 18, 2010
2,441
Catalina 310 Hingham, MA
I just did the Oberdorfer switch yesterday after SW seized. Piece of cake with a 3/8" wrench and a 90 degree and straight brass fittings ordered online (you can use the ones off the SW but one has to be ground down a bit for clearance). Close seacock. Works beautifully, about an hour's work.
Those fittings should be bronze not brass. Brass will have problems with the salt water and corrode.
 
Oct 3, 2011
825
Anam Cara Catalina 310 Hull #155 155 Lake Erie/Catawba Island
Stu, I ALWAYS, well almost,do what you say, Between you and Jesse, we as a group are very blessed to have you for guidance! Yes, Oberdorfer IS the Answer, the question is which one. I looked at Catalina Direct and they have the direct replacement for $422.78 and the one that needs modified for $292.55. We are getting ready to haul the boat for the winter :(, So I will have to check it out on the engine to get a good look at it. I will do the replacement when we get back in the water in the spring as the engine gets winterized.
For the XPB do I need to get new barbed fittings? Does all the gaskets, impeller etc, come with it?
Jesse is laughing about the winterizing comment..... Miss that Huh?
 
Sep 23, 2009
1,475
O'Day 34-At Last Rock Hall, Md
My Sherwood went after only 50 hours. But it was two years old. Apparently they do not like to sit idle.
No need to replace the barbs,just grind the edge down a little bit so it can turn.
First time you replace the impeller, remove and discard the c clip.
I used the modified ober and it fit perfectly.
Most importantly, the @#$/&*$#@ engine to pump gasket DOES NOT come with it. I had to reorder one and lost 2 weeks and shipping charges. Do it asap, you will feel better about the reliability.
 
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KZW

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May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
The direct replacement unit, which I used - before the huge price increase, came with the gasket and impller. No issue with barbs, no grinding. It was a straight drop in.
 
Sep 4, 2014
4
Catalina 310 Kemah, TX
I'm pretty mechanically challenged so I used the drop-in model. It was quite easy, less than an hour and I changed the belt while I was at it. The impeller came with it, but I did have to order the gasket.
 
Oct 3, 2011
825
Anam Cara Catalina 310 Hull #155 155 Lake Erie/Catawba Island
Did you order it from CD?- Catalina Direct?
 
Sep 4, 2014
4
Catalina 310 Kemah, TX
I got mine from Depco Pump Company. I called them to order and they told me what I needed and what I didn't need.
 

KZW

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May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
Deco Pump Company are good folks and spent some time on the phone with me helping me out when I did mine
 
Oct 3, 2011
825
Anam Cara Catalina 310 Hull #155 155 Lake Erie/Catawba Island
Was Associated Diesel and depco pump the no modification pumps? The boat will be hauled Wednesday and we will order the pump soon to install after launch in the spring.
 

KZW

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May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
I believe both of them carry both pumps. If you search, yo can find my posting on this which discusses both pumps and how to identify them when ordering.
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
The N202M-16 is the pump that requires modifications and should be less than $300. The N202M-908 is the drop in replacement and costs close to $500.
 
Sep 4, 2014
4
Catalina 310 Kemah, TX
The pump I got from Depco was the N202M-908 (no modifications needed). My recollection though (its been a bit less than two years) is that there was very little price difference at that time, but they didn't have that model in stock. They said it would take three weeks, and it showed up about 6 days later.
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
you might want to ck the gear adds on this site ...there may be on for sale