Metro Detroit area. Looking for help with carb rebuild, adj, etc

82 XJ1100J, 14000 miles, performance has gotten worst over the last 2 years. But it has always run acceptably. Then 120 miles back, after a fresh fill up with rec fuel, rode home 2 miles and parked it for a week or so. Next ride, it would not idle, at all, period. It was very finicky throttle work to keep it running I assumed bad gas, poured in some Dri gas and Seafoam. Seemed to run mostly better. Lousy fuel economy though.

Today, after about 30 miles, went back to running like crap and would not idle. Filled up again with rec fuel and drove home with no improvement. My guess now is that the Gremlins of Carb repair maintenance are here for their pound of flesh. Fuel economy was 32 mpg, I normally get around 36 - 38.

Also don't know enough about adjusting the valves on these beasts, so that could possibly be an issue.

Carbs are not my strong suit, so I could use help or could host a carb clinic if others were in a similar situation, naturally that would require a carb guy. is anyone interested in any of this scenarios?