Re: Does any one know what's missing or what goes here?

Posted by HH56 On 2013/10/10 11:19:19

Someone will need to check me on that particular carb but from your description, I believe it is just a small round press in screen to keep out large debris particles.

Once car starts and vacuum is present, the hole and screen provides air flow so the vacuum can pull the ball into it's resting place. Once ball is "home" it blocks the passage and no more air will flow. When the engine stops, vacuum goes away and lets the ball drop into position for the next start.