So I had the bike running pretty good and I now have about a tank through her. I fired it up yesterday to go for a spin and it is now running extremely rough. Sounds rough, and the the motor will jerk pretty violently. It is like the feeling after getting a flat in a car. It is coming from the motor even at an idle it is real jerky. Feels like it is out of balance or something. From the 5-15mph range it feels like it is going to rip off the frame. Any help on where I should start to trouble shoot?