another carb rebuild question

[jeff1005]

I bought the carb rebuild kit because my carb kept leakin out the overflow.When I took it apart I didn't see an o-ring at al,except for the ones on some of the parts,with the rebuild kit I got an extra o-ring and I don't know where it goes.Does it go somewhere near the needle valve?thanks

 

[Wildcard2]

the float seat will pull out if you undo the small phillips screw, that is likely where it goes.