This is very common.  I always add some "Sea Foam" motor treatment to my gasoline before trying to start the engine for the first time.  It is recommended to drain some gas out of the carb also with the scew at the bottom.  This is because the tank is coated on the inside with a film to protect it from the salt air during shipping.  The film will dissolve in gas, but sometimes it is like jelly and clogs the low speed jet.  Worst case you need to clean the carb.  You can also check you are getting gas to the carb by disconnecting the line at the carb (be sure to have no fire around and an extinguisher handy).  I have also seen the petcock not set to open (but still get some fuel through).  The air mixture may not be set lean enough for it to idle properly, also.  Hope this helps...I know it is frustrating.