This engine came with 2 different carbs. Walbro and Nikki. The Nikki carb has a very fussy float plate! I fight them often! Usually there is a problem with the odd gasket that lifts the flat plastic plate and causes a very low fuel float level in the carb so the only way it stay running is to have the choke on. The main fuel jet on both carbs is up inside the threaded area of the bowl nut. When the main fuel jet clogs...and it only takes a speck of something you also get the symptom of having to use the choke to keep it running.
Main fuel jet is item 117 Nikki or Screwed into item 142 Walbro of the of the above link depending on which carb you have.
The plate I am talking about on the Nikki carb is item 135. The fussy gasket is 137A.
THE threaded area is where all the main fuel supply is drawn from the float bowl. All that must be free of obstructions. Until this is clear and orifices / jets are not obstructed; your going to be running on choke....
Thanks for choosing FixYa,