Fuel Pressure from Tank to Outboard

[smclaren]

Hi Guys

I have fitted (semi permanent) a 75lt fuel tank up front in the cabin area.

Works well but I do notice that it slowly looses fuel pressure to the outboard .. particularly at speed. The priming bulb goes flat ... and the engine begins to starve. I have found a couple of loose-ish fittings that I have nipped up which is probably the issue here.

But it got me thinking about fuel line pressure to outboards.

How far away can a tank be before pressure in the fuel line becomes an issue ? Would a second priming bulb at the tank end help with maintaining fuel line pressure at all ?

Thanks

Steve

[FishHunter]

There is no positive pressure the fuel pump sucks the fuel out of the tank if your bulb is sucking flat then you have a restriction in the line somewhere. What size motor and what size fuel lines? Also do you have a vent in the fuel cap that you open when the motor is running?

[Noelm]

correct, the bulb going flat indicates a restriction between the bulb and the tank pickup and vent (assuming your bulb is OK and pointed the right way) is you new tank vented OK? if your motor is a bigger HP, then it is possible that your fuel line is too small (need bigger diameter) or the tank is too far away if you have a smaller HP motor, having 10 primer bulbs will not help, one you have primed the motor to start, the bulb is "out of play)