[wera710]

So there I was...working on the belly of my RV-8, cleaning off my latest attempt to commit genocide on the local bug population...when my fuel vent spewed all over the floor.

Stuned, I thought, wow, God must really love gnats, for revenge is theirs!

Thing was, it was like clock work for about an hour. Left side vent only. High velocity spray of fuel, leaving about an eight inch circle of misted fuel on the floor, Which I might add, nicely cleaned up the ground-in oil left there from the last tenant.

Is this normal when you have nearly full tanks and its Blistering HOT in the hanger? As I watched it happen again and again I started to wonder what this was COSTING ME! lol.

 

[rvator_md]

Scott,

I too had the same problem on my -6 and oddly enough it was the left tank.

This past condition inspection, I decided to pull the tank and resolve this matter. Like you, how much is this costing me?

To my surprise, I found the nut was not tightened enough on the vent line inside the tank. I checked the flare and it was fine, so I tightened the nut and sealed everything back up. Once back on the wing and full of fuel, no fuel venting on the floor.

I suspect this to be the same problem in your tank. Inspect the flare as well as this may be cracked and allowing fuel to enter the vent line.

Good luck.

 

[Geico266]

Try leaving a 1" gap between the fuel & the rim of the tank.

That or quit rubbing so hard!

(First sentence is a good suggestion, second sentence is a joke about rudding too hard and creating heat to expand the air and push the fuel out the vent tube. Seems I need to explain things better for some CA VAF members to follow.)

 

[Brantel]

Second the vent line B nut not tight on the inside can cause this.

A friend did not think to check this on his quickbuild and had the same problems. Tore down the tank and found the B nut loose on the vent line bulkhead in both tanks.

If this is loose, fuel will creep in over time and when the tank warms up, it will perk fuel out.

Quickbuilders should double check this nut!

 

[wera710]

Outstanding. Thanks for the advice!

 

[Jamie]

Fuel will expand considerably when it warms.

Mine has done it occasionally, but really only when it fills up. Sure, the b-nut may be loose, but you may just be overfilling the tank. Make sure your vent line is still at the very top part of the tank.

The true test is when the tank is not quite full and it's doing it, remove the fuel cap. If you get avgas all over you and your wing, the problem is simply that you put too much fuel in. If you remain dry the problem is probably the b-nut. Ask me how I know.

 

[wera710]

The odd thing was the we had filled the tank to about a figners width, or half to 3/4 inch below the filler neck. Thats why it struck me as so odd. I had to "laugh" when it was happening as I started doing the math...SPURT...there goes 50 cents....Spurt...theres another 50....lol.

Figures I'd get back into avaition again when fuel hit $6 a gallon. LOL. I used to whine when it was $3!!!