on the driver's side of the carb i adjusted the idle screw for 800 rpm....its been like this for over a year...i noticed a high idle, around 1200-1400 rpms....so i checked the idle screw, and there is a gap between the screw and the metal piece....when i push the piece back against the screw, the idle goes back to normal....but when i rev it, it gets stuck at the high idle with the gap again

 

I had that problem last summer, i added a second return spring...

 

I had that problem a few months ago and for some reason the idle control solenoid was causing it .