Adding larger fuel tank

[Bricklayer]

I'd like to add a larger fuel tank to my 6.5hp motor. Currently it will run about 8 hours on a tank but I'd like to not be lugging gas tanks into the bush. 1 trip every couple days would be nice.
This is the motor I have

16720

It has the fuel line comming in the top of the tank. So it draws the fuel into the carburetor with vacuum from the valve and air box. So I, thinking of using a plastic marine fuel


If the line is primed with a primer bulb and the fuel tank is sitting 1' below the carb on the ground will it be able to draw the fuel to the carb?

[maple flats]

These are what I use:
https://www.surpluscenter.com/Engines/Engine-Accessories/Fuel-Tanks-Caps/4-5-Gallon-Red-Fuel-Tank-w-Fuel-Shutoff-Valve-28-1836-R.axd
I just build a wooden rack beside the engine, setting on the ground. Each tank is 4.5 gal and it comes with a shut off valve and below that is the fuel spout to attach a gas line to. I mount mine about 3-4" above the engine. I only use 1 on each pump but you could just as easily connect multiples as long as they were at the same height, just use tees to string as many as you want.
On my 6.5 HP Honda, running the vacuum at about 2/3 throttle I get about 14 hrs on a tank. I also watch the forecast and when collecting late afternoon I only add enough to run until it is supposed to freeze and I try to have the pump go about 2-2.5 hrs past that. I just do the math, I multiply the hours I want it to run times 3.1 hrs/gal and I try to guess that. I carry my gas in 2.5 gal cans, one in each hand. It's pretty easy to get quite close. If the forecast shows a freeze just before or within 3 hrs of sunrise I run it straight thru. I go to collect 2x a day. If you only want to go once a day, just tie 2 tanks together.

[n8hutch]

I think what Dave is trying to say is mount the Tank in some fashion above the engine. I have to side with him, it might lift the fuel once primed from ground level but I doubt it personally, the needle and seat float system relies on a gravity feed. I can't think of too many engines I've seen that had a fuel tank below the carburetor that didn't have some kind of fuel pump, mechanical or vacuum induced pulsating fuel pump.