Volkswagen Repair: Fuel problem, gas cap, plastic insert

Question
My 72 VW Super Beetle is having a problem.  As I try to accelerate it hickups a little bit and doesn't really excelerate all the well, until I hit higher RPMs.  My fuel filter is relatively new and still really clean.  I took it off and looked for any blockage inside, but it was clean.  I was leaking gas out of the gas cap, so I replaced that.  The parts store gave me the one they said should work for my car, but didn't fit.  I got a different one (not made for my car) that fits and makes a tight seal.  My car was running relatively well before I bought this gas cap, although my fuel economy was very poor. (proabably fixed by the gas cap.  It's hasn't been long enough to tell.)  I believe my problem is either an incorrect gas cap, or perhaps I need to repair/replace the carburator.  Any information would be greatly appreciated.  E-mail me back if you have any more questions.

Answer
Mike, thank you for your question.  sorry it took so long to get back to your question.  The problem you are having is the same one I was having with a 77 Beetle, too (until today).  First, the gas cap should be vented.  The rest of your trouble could very well be the points.  You will need to adjust them as per the Bentley manual (1970 -1979, Type 1).  Also check the plastic insert and see if it is damaged.  Make sure the cap and rotor are clean, if they are not, you can clean them but it is best to replace them.
Hope that helps