"nobody" writes:

[...] Sure enough, my mechanic and I found the left outboard tuel
tank vent tubing was almost completely plugged, way up inside, about
halfway between the vent port and the tank. [...] This is a good
argument for capping the fuel vent ports when the airplane is
parked, just like we cap the pitot tube. [...]

How would you do that with an Aztec? Each fuel tank's vents open on
the underside of wing, one exiting in a big hole in this ceramic-like
block, and a second little vent tube to drain liquids from the big
one. Both point mostly down (and there are eight of them total).

- FChE