That whole Dikes idea sounds good but with most of these carbs, you don't have room to get something as wide as the jaws of a set of dikes around the screw head. I usually use a set of Needlenose Vice Grips to get them out, or an impact driver if there is still some slot left in the head. Then of course, I replace them with a firmer bolt.

~HoundDog

 

Your right there's not much room, but just enough to give it a 1/8 turn each time, it worked for me on my carb and a friends that I also did.