I think the gauze helps to stop the 'spitting' of petrol out of the bell mouth when backfires through the carb (mainly kick starting) and a good idea it is too! But I can't help wondering how long it takes before becoming clogged up because it is also basically acting as an air filter as well. In our campervan we have fly screens across the windows which are made of a fine plastic gauze, I was amazed at how much better the airflow was when I removed one for cleaning. The same thing must be happening with the gauze on the carbs, and I wonder if this could also lead to a richer fuel mixture when the gauze becomes blocked?
