OK that's a Vangaurd engine. The open inlet is kind of an overflow. The inlet needle is not shutting off the fuel flow to the carb. On the bottom of the carb there is a float bowl. The float in that bowl is what raises the inlet needle to shut off the fuel flow to keep a constant level for the carb to draw from. It may just be stuck. Try tapping the float bowl lightly with a screwdriver handle. Or it may be blocked open with dirt. In that case the carb will need to be opened up and cleaned out, or rebuilt.
Rick
April 2006