Rpm's wont rev past 3500

[Heathcliff99]

I recently bought a new 2014 49cc ToaTao Vip scooter and i noticed my rpms wont exceed 3500. It currently has 573 miles. I can go about 30-33mph max but it takes a while and the rpms are always below 4k. I also lose a bit of power when i go up hills as well and my speeds will even drop to 20mph sometimes. A couple friends of mine have 50cc scooters and they seem to go 35-40 mph quite well, and they pass me on the road and hills with breeze. I changed the CDI out with a performance one that is blue, but i didnt see any change in the rpms. I also put in a performance coil and spark plug, but that only made it start better and idle better, it didnt increase my rpms or speed. I watched youtube videos of people riding the same exact scooter as mine and getting 6-7k rpms easy. So i know for sure that something aint right.