What's wrong with this picture

Gene T · #1 (**permalink**) 03-09-2010

Working on my new boat and decided to put in a new impeller. Engine was pumping fine but just didn't know how long the old one had been in. This is what I found.

zeehag · #2 (**permalink**) 03-09-2010

looks like it should look---if dont know age then change it out--they are inexpensive--and carry spares.....

JimHawkins · #3 (**permalink**) 03-09-2010

What's all that build-up at the bottom?

sailortjk1 · #4 (**permalink**) 03-09-2010

I'm surprised the blades are still intact.

k1vsk · #5 (**permalink**) 03-09-2010

It's almost irrelevant how old the existing one is as it cheap insurance and always a good idea to change it annually. Visually inspecting an old impeller can often be misleading as you can't see tears in the blades or a split or separation in the spline.

sailortjk1 · #6 (**permalink**) 03-09-2010

Guys, there is more going on here than a simple replacement of the impeller.
Look again at the picture.
Or is it just me?
I have never seen a housing that is oblong shaped.

buckeyesailor · #7 (**permalink**) 03-09-2010

any chance it sat idle for a Loooong time?........looks like a deposit of some sort to me.........but I know nothing.

Faster · #8 (**permalink**) 03-09-2010

That's totally normal, except that a couple of vanes seem to be bent the wrong way. The shoe at '8 oclock' in the pic is a normal part of the pump and is what ensures that water is forced out the outlet rather than circulate within the pump.

The vane reversal could have happened if the engine "kicked back" a bit when it stopped... Looks otherwise normal to me.

jrd22 · #9 (**permalink**) 03-09-2010

I agree with Faster, the housing is supposed to have that built up area. Why there are vanes going opposite directions I'm not sure about. If the impeller was incorrectly installed in the first place, with some of the vanes going the wrong way, I suppose they could have stayed that way if it was a long time before it was run. Replace with all vanes going in the correct direction and it should be fine.

tip · #10 (**permalink**) 03-09-2010

Once the pump starts turning, the vanes will flip and run the correct direction.

The pump probably rotated a small bit the opposite way, causing a vane to flip.

Gene - I like the fact that you decided to replace it based on not knowing how old it is. I will be replacing mine soon, even though the previous owned said it was "like a year old".