Motorcycle Repair: Carb Settings not covered in Clymer, yamaha warrior 350, 2001 yamaha warrior 350

Question
I am going through a 2001 yamaha warrior 350 carborator and may have adjusted something unintentionaly. there is a small brass rod protruding into the air flow from the lower right of the intake. it seems to go into the fuel bowl and has a very small pin hole at the top. i was removing jets to check and clean then when i saw the slot to adjust this mystery part and of course i tried to remove it. i it had scars from the previous owners adjustments so when i turned it and it did not remove itself i had assumed it was stripped out. i gave it a light tap to see if it would move out to catch a thread and it fell out.  

   i am wondering what this piece is and how do i properly adjust it back to factory? it does not state anything in my manual about it but it is pictured so i know this is still the proper carb for this machine.

Answer
Patrick, Some of the parts in the carb are not to be removed,this may be one of them. Some of these carbs use a brass tube for an accelerator pump. Thats why the small hole in the end for fuel to be expelled under acceleration and this tube may have been pressed in not to be removed. If the tube gets damaged and wont stay in place a new carb is about $350.00.