I did some research and I now am set on the px80. Waay more quality than the eBay/China kits and have much better porting and hardware. The balanced crank is also a huge plus as the eBay kits are almost never balanced. Plus for 109 bucks, you just can't beat the price. I'm planning on running a 36 tooth sprocket and a mz65 pipe, and with some mild port work and carb tuning im hoping to hit 35mph, which is already way too fast for the bike im putting it on lol.