Brown color in fuel

[JohnsonM50]

Ive gone over the fuel system on my Airborn tank to carb. The tanks sqweeky clean, the fuel line & prime bulb are new & the line from pump to carb is the same new.. Pep Boys fuel line. The Oil Im using dyes the gas a dark blue-ish green. Problem is the 1st cup or so comes out brown then its blue again. It almost looks like rust & the only ferrous metal there is the pump housing that is rusted outside but clean inside. [I will replace that with an aluminum one] Could it be that the fuel line is coloring the gas? Its the only part I havent used long term except the primer ball. Thanks.

[Mark75H]

Could be, but I suspect it is just the fuel deteriorating. I hate the crap we get these days.

[JohnsonM50]

Well, I got it off the motor & will let it sit awhile & sqweeze some out into a clean cup before the pump to see if its from the fuel line. Whats in the tank is staying the normal blue-green.

[mxp864]

I use vp fuel and yamalube.

last year i cleaned the tank, replaced the lines, and "rebuilt" the filter.

when it sits for a bit the fuel in the filter turns a dark brown. I assumed that it too was breaking down perhaps. It never effected the performance noticibly. I never paid it much attention after going the entire season without a problem.

[JohnsonM50]

I use vp fuel and yamalube.

last year i cleaned the tank, replaced the lines, and "rebuilt" the filter.

when it sits for a bit the fuel in the filter turns a dark brown. I assumed that it too was breaking down perhaps. It never effected the performance noticibly. I never paid it much attention after going the entire season without a problem.

Thanks. Yeah, this will start & run too, Im pretty sure its the line & have some clean fuel sitting in a piece to confirm.

[JohnsonM50]

This is definitely the fuel line. It appears the black coloring is leaching into the gas & theres tiny particles too. Coincedently the float needle failed in the carb, related? I replaced it.

[zul8tr]

This is definitely the fuel line. It appears the black coloring is leaching into the gas & theres tiny particles too. Coincedently the float needle failed in the carb, related? I replaced it.

How about using tygon yellow fuel lines that will stand up to alcohol and will not cause gas to discolor? Available at local lawn mower shops.