There may have been a small spring in the hole with the ball bearing too. The round disk part is called a welsh plug, you can get them from a rebuild kit for your carb. Figure out which model carb you have and go to Outdoor Distributors dot com and find a parts blow-up for it. That way you'll know if you need a spring and a ball or just a ball. By the way the 'smoke' you see is gas/air vapor.
