# My bait pump won’t prime?



## Fritz (Jan 17, 2017)

New boat is in the water and floating, I’m as surprised as you.

Meanwhile, I have a Rule 800 gph bait pump that works fine, but won’t pump water. Wait, if I close the shutoff valve, take the pump cartridge off and fill the housing with water, then turn the pump on, then open the shutoff valve, the pump works perfect, moves water just fine.

The boat doesn’t draft very much and the pump might be four or five inches above the waterline.

What do you guys think?

And thanks!


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## lemaymiami (Feb 9, 2007)

What water pick-up (scoop) do you have and where is it located? A few pics of your actual installation will greatly aid in making a recommendation... On my old Maverick (only 31 years old now...) I had to add a small brass tube (drilled into my scoop at a very slight angle to allow the scoop to get water when I'm running). I never had a problem drawing water when the skiff was stationary - only when running - and it took a while and an observer aboard for us to figure out just what was going on... 

Hope this helps - and "aren't boats fun"?


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## Finsleft258 (Oct 7, 2018)

Fritz said:


> New boat is in the water and floating, I’m as surprised as you.
> 
> Meanwhile, I have a Rule 800 gph bait pump that works fine, but won’t pump water. Wait, if I close the shutoff valve, take the pump cartridge off and fill the housing with water, then turn the pump on, then open the shutoff valve, the pump works perfect, moves water just fine.
> 
> ...



That bolded line is the problem. The pump you have is not self-priming and is designed to be flooded (i.e. below the waterline). Do you have pictures? This could be a simple modification.


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## firecat1981 (Nov 27, 2007)

How is it 4-5 inches above the waterline? Got a pic of the set up?


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## Fritz (Jan 17, 2017)

I made a scoop/strainer out of carbon, when I get to 10 or 12 mph I have enough pressure to prime the pump and she works fine.

The boat sits pretty high and that sill on my box is about six inches above the bottom of the boat, the pump is definitely above the waterline, not by a lot, but enough so it won’t prime.


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## firecat1981 (Nov 27, 2007)

No nonself priming pump is going to work well in that scenario. The intake needs to be fully submerged so the impeller gets a bite. You might need to reengineer it with a better pump.


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## Fritz (Jan 17, 2017)

Thanks Firecat, it did not occur to me that these pumps were not self priming.


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## firecat1981 (Nov 27, 2007)

We tend to go with these pumps because they are lightweight and cheap for our skiffs, but there are self priming pumps out there, usually used on larger center consoles or for wash down hoses. There are many to choose from, just gotta fit it in.

https://www.ebay.com/p/2303627340?i...MI853p1pe26AIVh5-fCh2r-gBTEAkYDSABEgKU5_D_BwE


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## RJTaylor (Oct 4, 2017)

Can you post a pic of the intake side from the outside of hull?


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## Fritz (Jan 17, 2017)

RJTaylor said:


> Can you post a pic of the intake side from the outside of hull?


I can, but not easily, the boat will stay mostly on the raft, but I might see if I can charge a GoPro and take a swim.

The scoop I made is small, but has seven or so slits in the front leading edge and should keep the pump fed while underway. When I hit about 10 mph the pump pressurized enough to work just fine.


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## Capt. Moose (Dec 12, 2015)

Have you tried putting the boat in reverse really hard when the pump is on. Sometimes you can get them to prime that way.


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## Jumbo Jet (Mar 18, 2018)

Man, I thought it was just me. Glad someone else has a similar problem and we can find a fix. My boat came with an Atwood Tsunami T800. If I launch the boat and immediately try to fill the live well, I won’t get a single drop. But if I just jump on plane for a second, it pumps fine for the rest of the day. Pump is lowest point of the bilge, right next to the drain plug.


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## Fritz (Jan 17, 2017)

I think the answer is these pumps are not self priming. If the impeller is submerged, she will pump, so as soon as I move forward with any speed, maybe 10 mph, I get enough pressure on my scoop/strainer to push water up to the impeller and she pumps. Or I can trick the pump by closing the SOV and filling the pump housing myself.

I was hoping it might be maybe a vacuum leak or something I might have done badly in the rigging.

I might be able to lower the pump enough by removing the SOV, but I kinda like having that, so maybe I will just live with it.

Thanks for all your help.


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## Jumbo Jet (Mar 18, 2018)




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## permitchaser (Aug 26, 2013)

I don't understand why you need to prime any pump. If my boat is on the trailer and i flip the switch the pump runs. If theres water around it then i flip the switch boom the water comes out. This goes for bilge and live wells.
My live wells they are through hull and if its in the water they pump whether I'm running or sitting still


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## firecat1981 (Nov 27, 2007)

I don't think you are understanding the issue permitchaser. His design has a fundamental flaw where the pump sit above the water, not in it. So it is surrounded by air. Without the ability to self prime the pump will spin, but not suck up any water.


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## Tautog166 (Jul 7, 2018)

I have to give my pump a boost to get it going. Turn pump on move forward a bit and it gradually gets going. Just have to do it first thing in the morning and it’s good for the rest of the day. I have a recirculating pump as well so the fill isn’t constantly running, only when I refresh the water. So after it’s primed it stays that way all day. Just something you’ll get used to.


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## RJTaylor (Oct 4, 2017)

Fritz said:


> I can, but not easily, the boat will stay mostly on the raft, but I might see if I can charge a GoPro and take a swim.
> 
> The scoop I made is small, but has seven or so slits in the front leading edge and should keep the pump fed while underway. When I hit about 10 mph the pump pressurized enough to work just fine.


Don't go through the trouble, as I finally figured out the pump looks to be in the console. Can you add a 90* fitting? That might possibly lower the pump a bit, and allow it to prime easier.


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## permitchaser (Aug 26, 2013)

firecat1981 said:


> I don't think you are understanding the issue permitchaser. His design has a fundamental flaw where the pump sit above the water, not in it. So it is surrounded by air. Without the ability to self prime the pump will spin, but not suck up any water.


yea I thought about that. But if its a new boat take it back and get it fixed


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## Guest (Mar 27, 2020)

permitchaser said:


> yea I thought about that. But if its a new boat take it back and get it fixed


Home built Lightweight Conchfish. Draft is negligible so at the level the pump sits it will not pull the water.


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## Fritz (Jan 17, 2017)

Great video Jumbo Jet. I now understand my problem, it’s this stupid stupid shallow draft skiff!

I can prime the pump manually or wait until I’m moving to get it to prime itself. I will adapt. I’m scratching my head wondering why I didn’t know these pumps acted this way. I’m also wondering what other really basic stuff I don’t know.



permitchaser said:


> yea I thought about that. But if its a new boat take it back and get it fixed


. This is a good idea! I have some concerns however, that the builder might turn out to be an idiot, I might like his repair even less then I like the original problem.


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## Water Bound (Dec 12, 2018)

One of these and a horizontal install might help with these super skinny skiffs-https://thmarinesupplies.com/products/ez-pump-advanced-water-pick-up-system


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## Fritz (Jan 17, 2017)

Water Bound that is basically what I have. I made my own using a clay form and layering CF over it, then I dremeled some slits in the front and called it a scoop/strainer.

At about 10mph I have enough pressure to prime the pump.


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