More Oberdorfer Raw Water Pump Info

[Tom J]

Purchased hull# 57 Catalina 310 2012 Universal M25XPBC, decided to change the impeller in 2014 after 600 Hrs. Took the pump off the engine and replaced impeller the pump looks like the in the manual and is stamped Sherwood didn't see any model#. After replacing the pump I looked to see why the impeller could not be replaced with the pump on the engine. With the pump on the engine I only need to take the 3 bolts which hold on the front plate from behind the pump take off the front plate pry out the impeller and replace. I did notice there was not a wearplate or circlip in the pump. Am I missing something maybe this not the original pump?

Thanks for any info
Have really enjoyed this boat and am learning the engine

I'm a little confused here. Are you saying you have a new engine in hull #57? My hull no. is #231, built in 2003. If so, perhaps you have a new style Sherwood pump. I too, used to remove the three bolts on the pump body, and remove the front of the pump, but that part of the pump was the body itself, and the hoses had to be removed first. Mine also did not have a circlip holding the impeller on.
If you have a picture handy, that would help a lot.

 

[Tom J]

I posted on this issue back in April or May. Fried my Sherwood (forgot to reopen raw water valve...long story) so did some research and bought the Oberdorfer from DepcoPump based on some recommendations from here. But I didn't read enough and didn't realize it wouldn't work with out some modifications. Didn't have time, skill or capability to do those mods so called DepcoPump and returned the Oberdorder. They had Sherwood for like twice+ the price. But it works just fine.

But next time I will be better prepared...I hope.

Cheers,
Jim

The beauty of the Oberdorfer that KZW used is that it is a drop-in replacement for the Sherwood on some M25xpb's, like mine. I had bought the Oberdorfer with the square flange, and ground it down on a belt sander until it looked just like KZW's.
I bought my Oberdorfer in May, 2013, and my diesel parts distributor said the round flange was not available from Oberdorfer.

 

[c130king]

Yes, I bought the Oberdorfer to replace my destroyed Sherwood because I thought that easy to open front access would be much better. I did not realize it had that flange/base that needed to be modified.

So I returned it. Went to my local marine hardware and they actually had a Sherwood in stock that they said somebody ordered and never picked up. It was the same price as what DepcoPump wanted for a Sherwood...nearly twice the cost of the Oberdorfer.

But I was supposed to depart on a trip that day so I bought it and had it installed and working within 25 minutes of having my credit card swiped.

But now that I know about that new Oberdorfer with the base that fits the M25XPB I will go that route next time.

I put about 250 hours per year on my motor so I will get a feel for how long this pump will last.

Cheers,
Jim

 

[buddybear]

I'm a little confused here. Are you saying you have a new engine in hull #57? My hull no. is #231, built in 2003. If so, perhaps you have a new style Sherwood pump. I too, used to remove the three bolts on the pump body, and remove the front of the pump, but that part of the pump was the body itself, and the hoses had to be removed first. Mine also did not have a circlip holding the impeller on.
If you have a picture handy, that would help a lot.

The boat was built in 2001 and we purchased it in 2012, it is the pump body that I removed. Sorry for the confusion, this is my first diesel engine so I don't know how long impellers should last when I replaced it it had at least 600 hrs and looked fine. Seeing posts of changing to the orberdorfer pump but would like input on people who have kept their original Sherwood with success. We use the boat quite a bit.

 

[Tom J]

Buddybear, our Sherwood failed somewhere around the 1,000 to 1,100 hours mark. For a while, we did a lot of cruising, and I would change the impeller after every cruise (typically 300 to 400 hours). Nowadays, I change the impeller at least every other season, even if it only has 100 hours on it. Some manufacturers recommend changing the impeller every year. The age of the impeller is just as important as the amount of wear and tear it has gotten. Trying to maintain this kind of schedule with the Sherwood is a PITA, which explains why the Oberdorfer change-out is so popular.

 

[buddybear]

Thanks for the feedback will purchase The Orberdorfer pump and replace the Sherwood when it fails.

Thanks Again S/V Sweet Pea

 

[KZW]

The installed Oberdorfer is a thing of beauty!

 

[Tom J]

The installed Oberdorfer is a thing of beauty!

Very nice!

 

[peter_ms]

I have heard that the Ober actually pumps less water than the Sherwood. Does anyone know for certain?
Do the use different impellers?
Peter

 

[Stu Jackson]

1. I have heard that the Ober actually pumps less water than the Sherwood. Does anyone know for certain?
2. Do the use different impellers?

Peter,

1. http://c34.org/bbs/index.php/topic,5073.msg31397.html#msg31397

One of the things I hear all the time: "Sherwood pumps more water." So what?!? Really. I've had an Oberdorfer on my M25 (more like an M25XP now that I increased the size of the HX and added the alternator bracket upgrade!).

It simply doesn't matter.

Why?

'Cuz the Oberdorfer works just fine. And, it's a far SUPERIOR pump in terms of materials and longevity.

2. Yes. But again, it simply doesn't matter.

There have been hundreds of posts on this "Sherwood vs. Oberdorfer" pump issue. Sherwood, AFIK, is a piece of crap. If I had one on my boat and I knew there was a better pump...MUCH better...guess what I'd do?

 

[peter_ms]

Thanks Stu

 

[Kaiser]

Note that older versions of the M-25 use a Sherwood with a mounting flange.

I have the older pump. Can this same (or another) Oberdorfer be retrofitted onto mine? Has anyone done that?

 

[Stu Jackson]

Yes. It is simple. You just remove the mounting flange and mount the Oberdorfer.

 

[SailFysh]

Nothing to it. Even I did it. Replaced the Sherwood with the Oberdorfer and all is well.

 

[VF84Sluggo]

I'm getting confused here...

For a Universal M25XP, what is the correct Oberdorfer pump: N202M-15, -16, or -908? BIG jump in price for the -908 compared to the -15/-16, as far as I can tell.

The local marina mechanic said that the Oberdorfor part number for the Universal M25XP is the -908, but I couldn't find that pump. I told him that Catalina Direct lists the -16. Now I see the -908 does exist.

Again...confused here

 

[JK_Boston_Catalina310]

I'm getting confused here... For a Universal M25XP, what is the correct Oberdorfer pump: N202M-15, -16, or -908? BIG jump in price for the -908 compared to the -15/-16, as far as I can tell. The local marina mechanic said that the Oberdorfor part number for the Universal M25XP is the -908, but I couldn't find that pump. I told him that Catalina Direct lists the -16. Now I see the -908 does exist. Again...confused here

The -908. The others require modifications to work.

 

[KZW]

I'm getting confused here...

For a Universal M25XP, what is the correct Oberdorfer pump: N202M-15, -16, or -908? BIG jump in price for the -908 compared to the -15/-16, as far as I can tell.

The local marina mechanic said that the Oberdorfor part number for the Universal M25XP is the -908, but I couldn't find that pump. I told him that Catalina Direct lists the -16. Now I see the -908 does exist.

Again...confused here

both the -16 (with the O-ring) and the -908 will fit. The water inlet and outlet fittings on these pumps match the fittings of the original Sherwood. The difference is you will need to cut the flange and elongate the holes to put the -16 on the Sherwood mount. The -908 is drop in, using the clamps you save from the Sherwood.

 

[VF84Sluggo]

I'm chasing this on a couple of threads. From the Toad website, the M25XPA parts-wise is like the XP, but is wired like the XPB.

So, it sounds like the M25XP folks on the C34 forum have been installing the Ober N202M-16 with no mods required. But maybe I'm getting that wrong.

Anyway, the Ober -908 is a LOT more expensive than a -16...BUT, if it's a drop in fit with no cutting, grinding, elongating, pasting, soldering, epoxying required, then it might be worth it. The whole issue now is which pump for a M25XPA?

 

[KZW]

I'm chasing this on a couple of threads. From the Toad website, the M25XPA parts-wise is like the XP, but is wired like the XPB.

So, it sounds like the M25XP folks on the C34 forum have been installing the Ober N202M-16 with no mods required. But maybe I'm getting that wrong.

Anyway, the Ober -908 is a LOT more expensive than a -16...BUT, if it's a drop in fit with no cutting, grinding, elongating, pasting, soldering, epoxying required, then it might be worth it. The whole issue now is which pump for a M25XPA?

All I can tell you is it was drop in, easy, on the XPB. I paid the extra, and it is a lot extra, for the drop in. The mounting plate on the -16 will require grinding to fit the XPB. I'm not a mechanic and not great with tools. I was very slow putting it in. It was less than half a morning, including clean up and run check.

 

[VF84Sluggo]

Well, I'd pay the extra bones for the easy fit. I'm just not sure right now what fits an XP'A' version of the M-25, if a -908 is required for a no-mod fit.

Perhaps the version of the Sherwood that is presently installed hold the key...but how the heck to know this?