Hi all, I've had my Huasheng 4-stroke bike for a while now, and I use the 32-tooth sprocket with it. It gave me about a 5mph boost over the stock one, but I see people on here and YouTube boasting about their 30-40mph bikes?? How does a guy go about getting that kind of speed from the 4-stroke? I looked into a shifter kit but it's just too expensive for me to justify getting it. So what do you guys recommend for aftermarket parts to get me going faster? Thanks a ton!