I still haven't yet figured this out completely, however, it's definitely an air/fuel issue. Like I said, taping over part of the air intake on the airbox stops the bogging issue but it still only goes like 20 MPH. It needs to go faster.
One issue I'm dealing with that may be partly causing it is that the muffler will not go on tightly. Does anyone know the size of the nut that keeps the end of that thing on because the one I have can be pulled off with a little effort without even unscrewing it. That makes for a very loose muffler.
Also, I bought some tubing at a hardware store today but there is no way I can attach it to the back of the airbox to restrict air like the original tubing was supposed to do. I'm either going to need to get an original piece that's fitted correctly or I'm going to have to upjet, which I think may solve the problem.
That said, if anyone has any spare jets lying around for a bing carb that are larger than size 52 I'll take them off your hands for the price of shipping and say, 2 dollars each? Otherwise I'm going to have to order them from mopedwarehouse or something.