I have a 1991 xr80. The bike starts and run good, but it will not idle. I have removed the carb and cleaned with compressed air, including the jets. The carb is stock as far as I know. The needle clip is in the middle position, I have installed an inline fuel filter, And I have also drained the gas and put new gas in the tank. After trying all of these remedies, it still will not idle. The idle screw is turned all the way in for what it is worth. Any help would be greatly appreciated since this bike is for my daughter and she is having trouble keeping it running.