Red, I do not think you can expect a carburetor in that condition to work even as well as yours does. There are normally drillings coming into the side of the passage the main jet screws into. I can't visualise what your plastic sleeve has done to these, but in my opinion it is not worth thinking about anyway. You need a carburetor that has all of the parts, in original condition. From what you have said your carburetor's only usefulness would be as a source of spare parts.
I am not saying that your cobbled carburetor cannot be made to work, by analysing the status of each fuel and air passage in the carburetor, determining whether your cobbling has affected each of them, then designing a form of cobbling that will allow the carburetor to work after a fashion, for a while. However Outdoorking supports good workshop practice, and this does not include holding damaged carburetors together with pieces of plastic tubing in crucial areas.
