If the plugs your referring too are on the "tower" next to the main jet "tower" underneath those are your pilot jets. Those plugs should be installed for the carbs to work properly and need to be removed to clean the pilots jets out for a proper carb cleaning. The plugs are likely metal and held in with an o-ring on your carbs though some bs34s have rubber plugs. They might be a pita to get out so make sure you got a hefty pair of pliers. Under the main jet/washer is another needle jet basically. To remove it you must remove the top of the carb and remove the diphram/slider and needle. Then after removing the main jet and washer you can take a wooden dowell and tap it using a hammer against the needle jet and it will come out in the throat of the carb. Those were immaculately clean on my carb but definitely worth a look. Also ensure all your diaphrams are in good shape while your at it and make sure not to get any cleaner on the diaphrams. In the meantime try this link :
www.thegsresources.com/gs_carbrebuild.htm
Those are basically the same carbs and provide an excellent teardown/rebuild process with pictures.
