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When I open my canopy I get the smell of Av gas. While I like the smell of Av gas, I do not like it in my cockpit. I can find no leaks in the fuel system. However, I do have the vent for the tank coming out of the bottom of the cowl. I am guessing that the evaporating gas from the vent finds its way into the cockpit. Does anyone else smell Av gas when they open the cockpit?

Have you checked the fuel tank fittings under the tank? Every once in a while I get a smell of 100LL and notice a fitting may have a little seepage. Not enough for me to chase after as it normally happens on bitter cold days and not enough to leak.

It's nothing I really worry about. If that's the worst thing I smell on a normal flight I'm doing pretty good! :mrgreen:

I get the same thing, but after repeated checks, not a single leak or drip anywhere. I'm thinking it's just fuel vapors from the vent. My vent doesn't go out the bottom of the cowl, but I'm in the process of changing that, so I'll see if anything changes.

Mike Smith
Sonex N439M

Sonex1414 wrote:Does anyone else smell Av gas when they open the cockpit?

Sure do....always.

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Fastcapy wrote:I always have a slight smell, however I could tell right away when I had a leaky tank a few weeks back because it was stronger than usual.

Just one of the reasons I would prefer wing tanks over the Sonex tank design and location in the cockpit.

I know owners who have had passengers get nauseous while flying due to the smell of fuel in the cockpit.

I've never had even a whiff once the plane is being prepped for flight, and surely nothing while in flight. Mine is just a smell when the canopy is first opened after sitting for a while.

Mike Smith

I don't ever have any fuel smell in the cockpit unless I have some spillage during refueling. I've sealed off my fuel filler neck now and even that has stopped unless I really make a mess and don't get it mopped up.

Is it possible the fuel filler is the source of the odor?

Happy Landings
John
N50NX

When I had this problem, found it to be the filler plug, (thermos bottle type) not fully tight. If you can move it at all, it will leak vapors.

Think I will order on of those someone posted as being available on Amazon so can alternate allowing one to decompress for a while.

David A.

Assuming you have the fuel filler sealed off from the cockpit, the smell is most likely from fuel leaking around the filler cap. The necks are not necessarily round - the one on mine isn't. I have been told that the latest fuel tanks have a metal band so that the neck retains its shape and I think the cap has also been changed. You could just try blowing into the vent to see if the cap leaks.

Peter
Sonex 894

I'm still on my first gas tank plug after 400 hrs and I have noticed recently I'm tightening up the snap over feature and additional turn more than I used to. Rubber seal appears normal but I have found fuel in the box around the neck on occasion. That makes for fuel smell for certain.
Only other time I smell fuel is when I roll up to a stop and forget to shut off the fuel valve and the Aero-Injector will slowly drip fuel on the ramp. Other than that I would be looking for leak on the cockpit side of the firewall.

Larry