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Thread: thoughts on 3 fuel tanks???

  1. #1
    Here is what I'm thinking....let me know if you guys have any input or thoughts in general.
    For starters I have a 25 gal fuel cell in the bow of my boat (I know the placement sucks). I need to carry more fuel. Now, I carry a couple of 5 gallon cans in the back engine compartment for extra fuel. I'm thinking of putting two 14 gal (or there abouts) fuel tanks in the back under the gunwale next to the engine. I'm thinking of plumbing it so I have the motor running off the two tanks in back and as the day wears on using the existing red holley fuel pump as a transfer pump to keep filling the back two tanks. This would give me over 50 gallons of fuel on board which would be just spanky. I run long ski trips up and down the river where there is very few fuel stops. In fact NO fuel available within 20 miles of where I usually run the boat. I can't run it closer to the fuel on the river because of the god forsaken manatee zones (no wake) that plague the area around the marinas.
    So back to my plan. I suppose I need a dual inlet fuel pump for the two tanks in back. I could mount the pump over the jet intake behind the motor and draw from both back tanks at the same time. I guess I'd need 3 fuel level guages and then plumb the existing fuel pump to deliver fuel to the back two tanks when needed. This would allow for some better performance when the front tank was close to or at empty. Will the red holley have a problem with zero pressure fuel transfer? Or does it make a difference. I've never run a fuel pump as a transfer pump before. I know some types of fluid pumps aren't designed to run with no load on the pressure side. thoughts?
    You guys with dual you draw from both tanks at once, or do you switch from one tank to another? Anyone see a way I could get away with this with just one fuel pump? I don't.
    The good thing about a plastic cell in the bow is that it doesn't way shite when it's dry So when I'm running in a better location, or just a light day on the river, I can only fill up the two back tanks and maybe put a couple of gallons in the front tank for poops and giggles.
    Sure, I'll have to take out a bank loan before I hit the gas station, but that's boating :eat: If I gave a shit about fuel I would have bought a jet ski :sleeping:

  2. #2
    Senior Member
    Join Date
    Feb 2009
    okkkk...this is how my system works...i have 2- 12 1/2 gal side tanks & 1- 20 gal bow 45 gal...i have the front tank teed into the drivers side tank line in the back & the 2 side tanks teed together in the back with 1 line going to the stock hi-po fuel pump on the side of the block...i also have a shut-off valve on the front tank in the back incase i dont want to use it...i have n/p with fuel p/u...this set-up is the way the boat is on a 18' in-board ski boat---BBC w/jet...i hope this might help u
    P.S. if i was to ever re-do my fuel lines...i would run a fuel block in the back with 3 in-lets & 1 out-let with a shut-off valve on the front tank in the back...incase u dont want to use it

  3. #3
    I have two tanks. One on each side. The motor draws fuel from one tank at a time. It has a solenoid valve that connects the fuel pump inlet to the different tanks.

  4. #4
    Sooooo....I'll run a new fuel pump in the engine compartment and draw off 1 saddle tank at a time through a selenoid selector valve, just like on a truck. I'll wire the selenoid up to the dash so I can select from each tank. I'll run saddle tank A to empty, then switch to saddle B. When I start running saddle B down I can transfer from the bow tank to continuously fill up saddle tank B until all the fuel is gone at which time I'll be either heading for the dock or looking for a tow. The back fuel pump will be hooked to ignition, and the bow fuel pump will be wired to a manual switch for transfer. The only pitfall with this would be if I forgot to turn off the transfer pump I could over fill saddle tank B. I could simplify it and run just one saddle tank and just keep transfering from the bow tank as needed. This would eliminate the need for a selenoid valve but would probably limit me to 40 gallons or so, which should be enough. This way I'd only have two fuel guages and one switch instead of 3 fuel guages, 1 selenoid valve, 1 switch, and a friggin Partridge in a pear tree. Maybe I'll just keep one side of the engine compartment as storage.

  5. #5
    Senior Member
    Join Date
    Feb 2009
    u r trying to make the running of 3 tanks a real i stated in my earlier post...if u run a fuel block with 3 in-lets & 1 out-let & a shut-off valve for the front tank...u will have alot less bunch of wires, switches, gages etc...1 electric pump to do all the work...all the tanks wire into 1 gage & no switches...just 1 shut-off valve for the front tank, in case u dont want to use it...the 2 side tanks will feed together and after u think they are low, you can open the valve & feed the front tank...soooo much easier!!

  6. #6
    reccomendations on a fuel pump?

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