I bought an F80 from dax. I've got an NGK 7 plug and an RT carb. The fuel I'm using is 91 octane, 20:1. At low speeds the ride seems choppy. At first I had a .65 jet in there and swapped for a .7 and that made it a little better, but the bike has a lot of vibration and it's choppy at low speeds. I also noticed that every component attached to the motor seems to heat up, which I did not notice on my last kit.