I am building my first gasser and have been reading many posts on venting the fuel tank.
What is the problem with using a check valve in the vent line. It appears there must be some reason that I found no info on this method.
Would't this essentially provide the same action as the fuel cap on a chain saw, weed eater, etc. Air goes in, nothing goes out.
It would, of course, have to be removed for fueling.

Just curious !