Fuel selector Off when parked?

[vwav8tr]

Hi all, is it best to shut off the fuel selector and wing selectors when parked? We noticed some fuel on the hangar floor that looks like it’s from the Carbs. Tanks at about half full of Mogas. Weighed the floats and all good. Hangar temps get into the 120’s here, sometimes causing weird things to happen.

[desertdave]

Personal opinion….. if the carbs go dry seals start to dry up, crack and fail. If your carbs are dripping fuel they need to be rebuilt, repaired or adjusted properly.
I was having similar issues till I rebuilt mine and I readjusted the float heights per the Rotax manual. Mine were set WAY to high.

[vwav8tr]

Update: Fuel return line was cracked and leaking. Replacing the entire line.

[atosrider]

was the fuel return line different material than the balance of the system? or different vintage?

[Delta Whisky]

In response to your question: I do turn off all three valves when parking overnight or refueling. Desert Dave's point about dry carbs produce cracked seals is valid but for how long will the lines be off? Just another opinion to consider.

[vwav8tr]

The return line looked pretty old, the line from the fuel rail to the metered orifice appears to be in good shape, the 5 year hose replacement is only 2 years old so I think I'm good. Also, I think I'll just shut off the fuel selectors after each flight. Having fuel on the floor is not very comforting.

[Danilo]

This! Carbs should not leak. My current plane lives with the fuel valve open all the time, one less thing to worry before preflight. ( I still check).


Personal opinion….. if the carbs go dry seals start to dry up, crack and fail. If your carbs are dripping fuel they need to be rebuilt, repaired or adjusted properly.
I was having similar issues till I rebuilt mine and I readjusted the float heights per the Rotax manual. Mine were set WAY to high.