Thanks for the replies. I'll check out that carb in a couple of days.
The motor is a couple of years old, I'm told. I just replaced the plug and wire with parts from Pablo at sickbikeparts. I'm waiting on parts to replace the fuel line, fuel filter, and chain tensioner pulley. I took a look down the spark plug hole and it looks pretty carbonized in there. Also, the inside of the gas tank has some rust. Should I be concerned about those issues? There's a distinct rattle, like a marble moving around, coming from my gas tank (I think) when I rock the bike forward and backwards. I haven't figured out the source yet.