Maybe.. But even at that, it should still rev up at least, albeit smoking like a freight train in the rockies...

Edit: I think I have officially ruled that it's getting too much fuel. The plug is wet-looking (after being ran for a couple miles) AND it's almost black, which I s'pose could be the heavy oil mixture, but that don't explain the wet. Moreover, now that I think about it, I had a moped that had an air/fuel mixture screw on the outside of it's carb and if you loosened it and allowed more fuel to go through (which i thought would make it faster at the time... young, silly me), it started running in a very similar manner. Dogging around, much less power, etc. And when tightened back, it began to run well again. Now the big question: What do I do about it? New carb maybe? I hate that because it's a BRAND NEW kit...