Catalina 350 International Association

Or you can just use a 1/2" street elbow and a short nipple, since the OD of 1/2" pipe is approximately 7/8". See photos at the beginning of this thread.

Ended up reusing the old sheet elbow on the left side 7/8 and new brass sheet elbow a Barb for the 3/4 side.

Will find a replacement when I get the old pump back from being rebuilt.

Rooster

and they said that was the correct size (1/2) and I must have something modified.

I see that this is a little older thread but I hope that I can stick my nose in and clear up (if there is) any confusion.
Depco is wrong and isn't necessarily as much the "pump expert" that it's always been made out to be.
I've supplied/installed seawater pumps on Universals for 30 years, and am a pump and Westerbeke dealer so I have "a little" background on this. I throw that out there only so that you know that you can take the following to the bank.
I know about the N202M-908 pump (why - see *** bottom.)

The Ob install kit IS NOT FOR the B-series engines. - the hose elbows are wrong. I have b!!t¢hed to Depco because they try to sell it to M-25XPB and 35B owners. When I explained that it doesn't fit the B engine the reply was, "You're the Universal expert, not us." (the Depco marine pump manager actually emails me for help if there's an unusual issue on a Universal.)

When installing the Ob M-908 on the B-series:

• Simply reuse your bolts and L clamps from the Sw pump.

• Additionally, use the round Wb gasket or the Kubota gasket (p/n 16264-88130) for the engine also works (see photo.)
  (The pump land is actually on the engine to mount a mechanical hour meter or a hydraulic pump for tractors and industrial applications.)

To reuse the hose elbows there's a mod - very minor, 5-minutes (if you are slow ) (because the ports on the Ob M-908 pump are closer together than on the Sw G908 pump.)

• See photos - with a Dremel or hand file, take down the square hub on the outlet (7/8") elbow so it's flush with the hose nipple.

• Then slightly round off the end of the hose barb on the inlet (5/8") elbow. Install and position the outlet (larger) elbow first, then the inlet elbow is able to turn past the outlet elbow (see photos.)

The elbows in the Ob install kit are simply brass PEX x NPT plumbing adapter elbows, and like the OEM Sw elbows (cast brass, not bronze) they are not approved for saltwater use. Bronze or RED brass is for saltwater but there are no suitable elbows made -- therefore we're stuck with inferior parts on our pumps unless you install bronze elbows and hose barbs or pipe nipples (but there are issues with the bronze hose barbs that are out there that I won't quite get into here.)

Many owners don't know that Westerbeke OWNS the Sw G908 pump -- that's why there's an inferior (iron) pump on the B engines instead of the superior bronze Ob pump. Sherwood can sell that pump only as a Wb part at Wb's ridiculous cost. Wb forced Sw to discontinue retailing its sister G903 (identical) pump and now can sell only the one that Wb owns.

Many owners also don't know that the very expensive Ob N202M-908 pump is simply its old standby, less expensive, N202-16 pump. But instead of drilling holes in the mounting flange, they machine it into a circle -- and can charge a $150 premium (list $443 vs. M-16 list $305) because the only competition is the ridiculously priced ($535) Westerbeke #42175/Sw G908 pump.

Another option for the B engines is to install a bolt-on N202M-16 pump (after some "manipulation" of the mounting flange) rather than the clip-on, round base M-908. I have long believed that's the superior option.

*** In fact, several years ago I got tired of owners having only the option of installing the inferior iron-body pump on their engines, so I came up with both round-base clip-on and bolt-on options (see photos.)




I showed them around, and the next year Oberdorfer introduced "its" round-base M-908 pump. WOW, what a coincidence, 'eh?) But they still haven't stolen my bolt-on design. After the hometown Oberdorfer company sold out to Gardner-Denver and are now Ingersol Rand, these pumps are a tiny portion of the business so I guess my bolt-on design isn't important enough for them to copy.

Having installed the Oberdorfer pump for about 2-1/2 years, I reinstalled my old Sherwood pump. Nothing particularly wrong with the Oberdorfer, but it only seems to last about 18-24 months before the shaft seals start leaking. Two rebuilds in 2-1/2 years. Both of them the shaft was scored, so it also required a new shaft. Not a big deal as the parts including shaft only cost just over $100 from pumpsandpartsonline.com, but the Sherwood seemed to last a little longer. The first Sherwood rebuild was 3-1/2 years after our purchase and about 400 hours. I assume that the pump was likely rebuilt or replaced by the original owner as the boat was 4 years old and had 450 hours on it at our purchase. 2-1/2 years and 429 hours later, the Sherwood began leaking and I replaced it with the Oberdorfer, primarily because of the ease of replacing the impeller. Since the failure mode appears to be leaking at the shaft seals for both pumps every year or two, ease of replacing the impeller does not seem that important. I believe the Sherwood has a higher flow rate as well, but I never had any overheating issues with the Oberdorfer as long as the HE was kept clean and RPM was below 3,000. I am going to rebuild the Oberdorfer and carry it as a spare for the Sherwood in case if fails on the 'road'. We'll see how long it lasts this time. Never had to replace the shaft in the Sherwood, but eventually it's iron casing will disintegrate.

I have a Sherwood pump that was removed to install the Oberdorfer. The Sherwood pump was good, not leaking. I have a new Sherwood impeller, a seal kit and a spare Sherwood pump housing and guts that can be used for parts. If anyone is interested, $100 plus shipping. Will send photos if interested.

I will take the lot. Please e-mail me payment details
Thanks
weiss@rowan.edu

So this past weekend I intended to change the impeller on the Oberdorfer pump for the first time...

I realized that through this entire chain of "how easy" this was from the front, that not a single person indicated that the job requires Snap Ring Pliers for an internal snap ring. Not really a problem, just a lost day with a trip to Harbor Freight for a new $4 tool.

Also, I realized that my impeller repair kit came with paper gasket (which there wasn't even a paper gasket on the pump when purchased new...but the kit didn't have the rubber O ring?

So whats the requirement to prevent leaks? O ring? Paper Gasket? Both?

Thanks in advance,

Mike

By the way I've still got two un-rebuilt Sherwood pumps...when I contacted DEPCO as mentioned in this chain I was told they don't rebuild them?

Mike, I’d just put the paper gasket on and snug down the face plate. Run it for a minute and check for leaks. If it leaks and you can’t find a suitable O ring quickly, just put a thin bead of RTV sealant on the face plate and toss the paper gasket. My C34 had a Universal XP with the Orberdorfer pump. I never used the snap ring since the impeller had a pretty tight fit between the pump body and the face plate. I only used the paper gasket and never had any leaks.

Thanks,

I left the o-ring, and added a paper gasket and had no leaks.

I just installed the Oberdorfer pump with the enclosed install kit (N202M-837). The paper gasket and the L clamp and screws where useful, the two brass elbows included in the install kit fittings were 1/2". My boat has two different size hoses for intake and outflow, 3/4" and 7/8", so I used the brass fitting on the original Sherwood pump on the new Oberdorfer pump.

The Oberdorfer pump pulley sits about 1/2" closer to the engine than the Sherwood so I just needed to angle the water inflow fitting to give more clearance between the belt and the hose.

KevinMc wrote: ↑Fri Jun 25, 2021 5:27 am The Oberdorfer pump pulley sits about 1/2" closer to the engine than the Sherwood so I just needed to angle the water inflow fitting to give more clearance between the belt and the hose.

The belt riding 1/2" out of straight alignment could be a problem. Any way to shim or otherwise get the belt back running in alignment?