carter bbd question

the part #23 in this pic( i have a non electric version pic is represenative...) should there be some kind of seal there i pulled a shredded o ring out from the well by the spring (#25) and no o ring in rebuild kit...

 

Don't recall ever seeing an o-ring on that piston.
Quick FSM check shows no mention either.
Maybe a PO was trying to do something..???
Air gap adjustment is critical, check and re-check when done.

http://i38.photobucket.com/albums/e121/348Win/c16ec412.jpg
http://i38.photobucket.com/albums/e121/348Win/07c32224.jpg
http://i38.photobucket.com/albums/e121/348Win/b2f58617.jpg
http://i38.photobucket.com/albums/e121/348Win/ffc4ba38.jpg

 

thanks. it ran with almost full choke didnt know if it had an internal vacum leak there. will continue with the tear down and rebuild