[Steeveedee]

If the carb has any kind of age I'd check the primary throttle shaft for a leak. It's quite common,and will give the idle characteristics you are seeing. Other things may be wrong with it, too. You can have it or get it rebuilt, and put in new bushings. It's cheaper to have them put in since the tools cost money and you may only do it once. I usually rebuild my own and have a carb shop do the bushings. Last time the guy squawked about not having the whole job. YMMV