My bike runs good at 20mph and starts within 10 feet. All is good till you hit 23mph then the motor acts like it wants to die like starving for air or out of gas. I put a new spark plug and wire in, cleaned the carb. cleaned the air filter, and put all new gaskets on the intake, carb, and exhaust and the problem is still there it wont go away. If you have any ideas please let me know.