probably the air port going to Carbs.
Bob aka Busterrm
I think your probably having the same problem I was having with the airbox on mine when I made the opening in the front of the box for more direct air into the box. The air port has a screw that tightens the clamp that holds the airbox in the port. Pull the airbox off and pry the clamp off the port and loosen the screw up some and the airbox should slide right on. Then take a 1/4 inch ratchet with a 1/4 socket and a phillips screwdriver bit that will fit in the socket and retighten it.
Bob aka Busterrm