New Tao tao 50 underperforming

[recoverypunk]

I have owned a Tao tao 50 before and it rode pretty decent with good speed and fairly awesome acceleration from a stop (for a 50cc). That bike was stolen so I purchased a new one and it seems to under perform compared to my old one. Its slower and doesnt have near the acceleration. Its particularly bad on hills. I adjusted the idle to just below back wheel spinning and that did a little but not much. Is there anything I can do to get this new bike to perform as well as my older one? The new bike is a 2013 model and my old one was a 2011...