I said left side but I meant the right side. It's a long tube like a snorkel and comes down 90 degrees to the right side of the engine where his right leg would be. It's to big to plug with a finger and has a plastic grid screen like thing at the end. I found the air tube on the other side.

 

If you have a later model 90 (past 2005?) it's the air intake tube for the stator area that they added to try to keep water and dirt out. Air box snorkel was the same through the years on the left side on the 2 stroke models. OPT