Tractor Repair: how to prime a tractor, gravity flow, uplift

Question
1960? 460 International has not been started for about 1 1/2 year.
How do I prime the tractor?  It has what I call an uplift carburetor.

Answer
  It does not need to be primed.  Fuel should gravity flow from the tank to the carburetor.  If it doesn't, there is something plugged up or the float is stuck in the carburetor.  If it sat for that long with the old gas in it, the tank should be drained and fresh gas put in.