198 surges at partial throttle cruise

Ok guys. Let me reclaim some of my observations here. After spending time anylizing the surging more... It's really clean running at idle and wide open. But after really driving it more it's more than that. The surging/stumble is just above idle. It's not 1/4 throttle. It's more like just at tip in or cruise. Could this be as simple as a carb adjustment. I found a receipt from 6 years ago where a new carb was installed.