Impeller ID Universal 5424 Need Help

Hagar2sail

Member III
So I believe our boat has an Oberdorfer water pump. Visited the local boat stores and couldn't seem to come up with a 1:1 replacement impeller. Don't see any model numbers on the housing, how do you figure this out and order them? I don't have any spares at the moment, which I know is just asking for it. Also, the manual talks about advancing a grease cup on the water pump, but I don't see anything like it? Is that because this is a aftermarket pump?

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Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
Sure looks like the "newer" Oberdorfer version with O ring, that replaced my '88 model with the paper gasket.

"Oberdorfer!".... "bless you"
 

footrope

Contributing Partner
Blogs Author
That is an Oberdorfer (202M? something), more than likely. I've never seen thumbscrews, but I like them. You can search for the pumps and probably find one that looks the same

Measure the depth of the chamber and the diameter across the chamber horizontally and if that matches mine I can provide an impeller part number, I think. I have to go to the boat Sunday or Monday anyway. Mine is a 202M7, by the way. The grease cup on mine is on the right side of the chamber. If yours is newer there may not be a cup.
 

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Christian Williams

E381 - Los Angeles
Moderator
Blogs Author
New models of the Oberdorfer no longer have a grease cup. Too bad, I always felt very historical when I usta have one.
 

Hagar2sail

Member III
Looks like the horizontal diameter is 1-31/32” and the chamber is 7/8” deep.

could use a new o-ring too.
 

debonAir

Member III
yeah that's the new style 202M-03 (the 03 means it has two bolts for the adapter plate you see to the left). The new style has a graphite bearing which supposedly lasts for the life of the pump... we'll see.

tip1 - that adapter plate is held on by four nuts on studs that are screwed into the timing gear cover there. The 202M-15 model has the same hole pattern as that adapter, so if you get a -15 you can actually take off that adapter and mount the -15 directly using the existing studs, and then you won't need the little shaft extender thingy the -03 is using inside the adapter plate

tip2 - that little metal can you see to the left has a spring loaded pin in it. That pin is what the governor mechanism - via the throttle, pushes against when you shut your engine off by pushing the throttle hard. The spring-pin pushes the throttle back to "slow" when you release the stopping pressure.

tip3 - I got some of the run-dry impellers for mine, but they seemed a bit too stiff (polyurethane?) and my original pump didn't prime with them so I went back to old-school rubber. (and had to use some KY jelly packed in the pump to get that to prime). My new pump ought to work OK so I plan on swapping one in this spring. I would think Hamilton Marine in Portland would have them in stock if you wanted one right away.

final tip: you don't need the little C clip on the shaft to hold the impeller on, but yours seems to not be there already. You'll know what I mean when you get a new pump...
 
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footrope

Contributing Partner
Blogs Author
If it's a 202M, Moyer Marine has impellers and for footrope, thumbscrew plates too.
Impeller: https://moyermarine.com/product/flexible-impeller-csob_02_63/
Thumbscrew cover: https://moyermarine.com/product/mmi-back-plate-kit-csob_10_370/
Parrothead: That's good info, thanks. And there is no reason to doubt Moyer Marine. I may order a couple myself as the local outlet wants $67+ apiece.

My 202M7 spare pump is exactly your dimensions Hager2sail. I found a number on my spare impeller "OBD 6593." A search on that number should turn up sites like Fisheries (Seattle) - $67+ and Marine Pumps Direct - a two-fer at $78+, so that Moyer price is pretty good. Now all you need is money!

Craig
 

Hagar2sail

Member III
Haha you always need money when boating! Thanks all. Looks like the plate is a MMI plate after seeing it on their site, ordered a few of their gaskets and a couple of impellers, so hope it works out! Keep ya posted.
 

markvone

Sustaining Member
tip3 - I got some of the run-dry impellers for mine, but they seemed a bit too stiff (polyurethane?) and my original pump didn't prime with them so I went back to old-school rubber. (and had to use some KY jelly packed in the pump to get that to prime). My new pump ought to work OK so I plan on swapping one in this spring. I would think Hamilton Marine in Portland would have them in stock if you wanted one right away.
Great info on the pump! Thanks!

The Globe Rubber Run Dry Impellers have a bad reputation. I got some before I learned this so I didn't use them. Globe Rubber makes a lot of the rubber products used on US Navy submarines so I thought well of them. Dooooh!

Somewhere I read to use Glycerol (Glycerin, Glycerine) as a priming and dry start lube. Worked like a charm. It's available at most drug stores for ~ $3. Has other uses such as an antifreeze, moisturizer for burns and as a sweetener that won't harm your teeth.

Mark
 

footrope

Contributing Partner
Blogs Author
I just ordered two of these 202M neoprene impellers from Defender.com. They are on sale during Defender's Warehouse sale. Their sale price ($38.24) is not as cheap as Moyer ($36.00) but Moyer doesn't give online shipping choices for USPS priority mail, they just list UPS options. Moyer also didn't have any sales tax showing in the total.
500540​
Oberdorfer Pump Impeller​

When I checked Defender shipping I could get USPS priority mail for half the UPS Ground cost. In the end, I ordered from Defender because shipping was a bit faster by USPS and I didn't have to give the special UPS/FedEx shipping address the Post Office requires for PO Box holders. But the costs ended up pretty equal due to the sales tax charged by Defender and the $2.24 higher cost for each. Go figure.

Locally to me, Fisheries wants $58+ each for the impeller before any shipping or tax.
 

Hagar2sail

Member III
Thanks, I actually ordered from Moyer last week, two impellers, and two of the o-rings for the MMI pump faceplate. Everything arrived on Friday, and I can confirm that the impellers fit, and the o-rings were correct. Ended up ordering from them simply because I was trying to source a new o-ring, and they seemed like the best fit. I am sure now that the thumbscrew faceplate I have came from them. I will say the shipping was not as friendly as Defenders.
 
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