Pontoon Boat & Deck Boat Forum

I spotted a nifty little setup in the back of my neighbor's truck recently when he was working on his boat in the driveway. It was a 5-gallon jerry can with a tiny attached 12V fuel pump.
I have a 25-gallon gas caddy that's gravity-feed through a 3/4" hose. Works good but there are times when I might need to pump gas above the level of the fuel, or deliver it faster.
I'm *considering* adding an external pump, or a submersible pump, or even using my raft inflator to pressurize the tank to push fuel out.

There are of course hand-crank pumps found on some gas caddies but my older tank doesn't have a place to mount it. It's also quite impossible to stand in the water and refuel a jetski while also turning the handle up on the dock. Alone.

Thoughts?

I thought a photo might be helpful.

I just use a shaker siphon. Works great. My neighbor in the cove has a gas caddy like the one in your picture. He has a winch setup to lift it on his dock so gravity does the pumping for his boats.

Nothing clever, I just use a cheap 12v automotive fuel pump with 3/8" fuel lines in/out. I just drop the suction hose into the gas can and the discharge hose into my boat tanks. I only use it when the boat is higher than the dock. Generally, I just use pre-EPA gas can spouts and just pour it into my boat tanks manually.

An older friend of mine has my pump right now. It's connected to his fuel caddy because he has difficulty lifting 5 gallon gas cans. I paid about $55.00 on Amazon. It is a generic version of the Holley unit that is rated about 140 gallons per hour.

https://www.amazon.com/gp/product/B07K7 ... UTF8&psc=1

Does 3.5 gallons per minute supposedly. It is fast though. I just set the 5 gallon tank on the boat and let it go.

I use the same jiggle siphon. Works great. We jury rigged a coat hanger to hold the first foot straight to reach the bottom of the gas container more easily.

guy48065 wrote: ↑

Wed Aug 12, 2020 9:38 am

I have a 25-gallon gas caddy that's gravity-feed through a 3/4" hose. Works good but there are times when I might need to pump gas above the level of the fuel, or deliver it faster.
I'm *considering* adding an external pump, or a submersible pump, or even using my raft inflator to pressurize the tank to push fuel out.

I understand how siphons work but they don't address my concerns.
I can't use the caddy to put fuel in my truck. Can't use it to gas up jetskis when they are on the trailer. Can't use it to fill my pontoon when fuel level in the caddy is low because my pontoon tank is higher than my dock.
These are all exceptions rather then the rule but I'd like this big tank to "do it all".

This looks like it would fit the bill!

https://tinyurl.com/yylv8yg2

guy48065 wrote: ↑

Thu Aug 13, 2020 9:14 am

guy48065 wrote: ↑

Wed Aug 12, 2020 9:38 am

I have a 25-gallon gas caddy that's gravity-feed through a 3/4" hose. Works good but there are times when I might need to pump gas above the level of the fuel, or deliver it faster.
I'm *considering* adding an external pump, or a submersible pump, or even using my raft inflator to pressurize the tank to push fuel out.

I understand how siphons work but they don't address my concerns.
I can't use the caddy to put fuel in my truck. Can't use it to gas up jetskis when they are on the trailer. Can't use it to fill my pontoon when fuel level in the caddy is low because my pontoon tank is higher than my dock.
These are all exceptions rather then the rule but I'd like this big tank to "do it all".

Yes, Sir that was the point of my post above. A small or large electric fuel pump will do the trick. Price depends upon flow rate - small inline fuel pumps cost $15.00 but only move about .5 to 1 gallons per minute. High flow pumps can get to 10+ GPM but cost $200. Mine took about 2-1/2 minutes to transfer 5-gallon can. You can connect it between your caddy and the nozzle valve.

It is important to realize that not all "fuel pumps" are rated for gasoline. Many are diesel only!

Marc

steve1313 wrote: ↑

Thu Aug 13, 2020 11:18 am

This looks like it would fit the bill!

https://tinyurl.com/yylv8yg2

Not for gasoline (in the description). There are many much cheaper pumps available that are also not for use with gasoline.

Marc K wrote: ↑

Thu Aug 13, 2020 3:14 pm

Yes, Sir that was the point of my post above. A small or large electric fuel pump will do the trick. Price depends upon flow rate - small inline fuel pumps cost $15.00 but only move about .5 to 1 gallons per minute. High flow pumps can get to 10+ GPM but cost $200. Mine took about 2-1/2 minutes to transfer 5-gallon can. You can connect it between your caddy and the nozzle valve.

It is important to realize that not all "fuel pumps" are rated for gasoline. Many are diesel only!

Marc

Marc it looks like you're the only one who's gone & done this. What you describe is similar to the setup my neighbor has. His pump is a "Mr. Gasket" inline chassis-mount unit but pretty much all the ones in the same general price range have the same specs.
I'm hesitant to insert a 12V pump into my hose because then I'll be forced to always use power to refuel. A simple alternate would be to drop a submersible pump & hose thru the filler neck but I'm squeamish about 12V wires being IN the gas. I realize that's how ALL modern high-pressure EFI fuel systems are but it still creeps me out. (Nearly all submersible automotive fuel pumps are mass-produced cheaply in China. Just sayin...)

Experimentally I think I'm going to test the idea of using an air pump to pressurize the tank. All it will cost me is $6 for a new gas cap + a couple bucks for a hose barb through it. I have several inflators to choose from.

I looked up the math and gravity feed thru a 3/4" hose at 2-foot drop is about 6GPM. That's my baseline. I'd like to find a way to pump UP 2-feet at near that rate.

Going submersible would scare me. Yes, both of my vehicles have submersed fuel pumps and have never blown up but......give it try!

If you invest in a decent size pump you are less likely to want to use gravity again.
If you connect the pump using quick connects, it's no biggie to install/uninstall often.

Using air pressure is possible, but will require several PSI to move 6 GPM uphill.

The valve on your fill nozzle was not designed to seal off against several pounds of pressure. Same problem with an electric pump. so you will need to use a simple manual valve. I would use a simple gasoline rated brass valve located at the Jetski end of the tube. Electric fuel pumps are perfectly fine being dead-headed until you shut the pump off.

The largest Mr. Gasket pump is still only 1.5 gallons per minute, so almost 3.5 minutes for 5 gallon can.
There are several out there at 2.5 gallons per minute, so I suspect that you could find a 6 GPM or even lager unit - but I have not tried.

You could get clever and rig up multiple small fuel pumps in parallel, then put the assembly in a box with one 3/4" connection in and one out. It wouldn't take much because each pump would use regular 3/8' fuel line piped to a 3/4". Some fuel line, stainless steel hose clamps in a Home Depot bucket, or a more elegant container.

For me, the extra fueling time with a smaller pump simply means that I have an opportunity to consume a cold beverage of my choice

Marc

guy48065 wrote: ↑

Fri Aug 14, 2020 8:52 am

steve1313 wrote: ↑

Thu Aug 13, 2020 11:18 am

This looks like it would fit the bill!

https://tinyurl.com/yylv8yg2

Not for gasoline (in the description). There are many much cheaper pumps available that are also not for use with gasoline.

Sorry about that! I didn't read far enough down.

guy48065 wrote: ↑

Fri Aug 14, 2020 9:12 am

I'm hesitant to insert a 12V pump into my hose because then I'll be forced to always use power to refuel.

You can draw through a shut off inline pump fine. It's very common to install one on older cars prone to vapor lock or that sit for long enough that the bowls dry out to install an inline pump and switch it on just for priming, then switch it off to let the mechanical pump take over and draw through it. The real problem you'd have is the restriction you'd get from the 3/8" fittings at the pump in your large hand pump hose. Maybe buy another hose and rig one as electric, one as hand pump so you can swap hoses.

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