So I pulled the carbs to check float levels and install #40 idle jets. Putting everything back on I realized that I can't remember what these two brass nipples near the intake of each carb are for. Is there supposed to be a vent tube for these? I don't seem to have any tubes left over so I don't know if I lost something or if they were missing.
You never can take enough pictures the first time you do a job like this!
Here is a picture showing the two exposed brass barbs: