Worn bushings in the throttle body will let the plate stick in the bore slightly off-idle, or it's possible that the throttle plate isn't centered in the bore if the bushings aren't the problem. Remove the carb, loosen the screws holding the throttle plate to the shaft, and tap it to center it. Then retighten the screws. Don't try to remove them completely- - - -they're peened on the back side to keep a loose one from falling into the engine.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!