Small Engines (Lawn Mowers, etc.): homelite xl2 gas tank, duckbill valve, oil tank

Question
Just bought old xl2 auto chainsaw.  Cleaned it all up and got it running. Question is, there are two holes in the gas tank at the top, one is the main supply line and the other hole is just open.  Is it supposed to have a line in it? Everytime I turn the saw on its side when useing it, it leaks gas all over the place.

Answer
That hole has a "duckbill" valve pressed in it, so the tank won't
build up a vacuum, and won't let the gas leak out.  Most lawnmower
shops can get one for you, or may have one, cost maybe $1.
The oil tank likely has one as well, so you will know what I am
describing.

   Fish