Actually, I just noticed that I have the same problem. Ordered the black 49cc kit, but the label on the engine says 68.5cc. Looking on their website, however, it seems as if the intake pipe from the carb to the engine is slightly more rounded on the 49cc model, and it is certainly rounded on my bike's engine. I think the Chinese company might make one label and put it on both models-- how would Zoombicycles make the same mistake twice?
For now I will just assume that I have a 49cc. However, when it comes time to order internal parts, I assume that I will need to know what I really have. Am I correct?
Jason