Fuel tank breather venting fuel.

[whereswoody]

TRY AGAIN, Ok fuel tank breather is venting fuel. Tank is 350 ltr under floor in 6.8 mtr plate boat. Breather is approx 800mm above outlet on tank. Breather line is approx 5 mtrs long with loop in line. Any thoughts as to why this would happen? If this goes up twice sorry but there seems to be an issue with sight not loading correctly.

Cheers

Woody

[tropicrows]

I take it the tank is full. Is the boat level or on a slope.

[whereswoody]

Yere tank full, happens towing, on water, almost like some sort of pressure issue???

[gofishin]

Explain what you mean by 'loop' - complete circle? Or inverted trap?

How full is the tank, up the filler pipe? Breather hose clear/can you see fuel in the breather line, or is it coloured?

Fuel expands quite a lot when it's temperature increases, which can create pressure in the tank if the breather is blocked (even by fuel trapped in the hose - which is then forced out of the breather by same pressure), but if the motor is running (consuming fuel) this obviously creates a negative pressure in the tank, so no fuel should be coming out the breather when underway.

How much fuel (coming out) are you talking about?

More info required. Explain your setup, pics etc???

Cheers
Brendon