Tao Tao scooter slow on acceleration

Hi ya'll

I have a 2015 taotao 49cc scooter. It is very slow to get going. I have to push off with my feet to get moving, then acceleration is slow, but does pick up speed finally as I go. I can achieve top speed of 35 mph, so top end is good, just getting going is hard and dangerous if at any intersection.
I have changed out the carb with a brand new one, and did nothing to fix the problem. Everything else is stock. I have bought a new belt but haven't put it on yet. Any ideas and help would be awesome.
Thanks
Terry
swally07