Mystery impeller

[Sailorman2]

Hi I'm new to the forum and had a question about an impeller. I have a Westerbeke 40 which has been terrific for the 25 yrs. I've owned it. I'm heading down the ICW soon and thought I'd put in a new impeller. I bought 2 so I'd have a spare. When I put the new one in it won't pump water. Put the old one in and it pumps fine. So I tried the other new one, won't pump. Put the old one back and it works fine. These impellers look identical to the old one. Please help.

[vmattiola]

Have you tried complimenting it? I've found I need to say nice things to my motor before I put new parts inside her.

[a64pilot]

It may be ever so slightly thinner and not be making a seal with the cover plate, it only takes a few thousands of an inch to break the vacuum if you will.


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[Sailorman2]

Thanks A64pilot, it's a Sherwood impeller kit #09959K. The same one I've been using for years. God only knows, I just wish he was with me.

[GordMay]

Greetings and welcome aboard the CF, Sailorman.

[a64pilot]

If you have a mic or calipers, measure it, or put them both on a flat surface and see if one is thinner.
I haven't had this happen to me yet, but I have heard of it before

[boatbod]

Does the impeller turn if you bump the engine over? If not you might be missing the key (assuming not a splined shaft)

[fallingeggs]

I have a W33, so my experience may or may not apply to you. Probably won't as your problem seems slight different, but here it goes...

I found a replacement for the OME impeller at half the cost. Was the same size measured with digital calipers. The only difference was the dang key / shaft. Westerbeke appears to have made a custom fitted key so they can screw us on the pump and impeller. No matter though as I was able to push the key out of the old and place it into the new.


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