So I just got home from a tour and ive been.

So I just got home from a tour and ive been helping her fix the things she cant do herself. She has a 1975 ford courier that ive been using. It started boging between 1200 and 1500 rpm. I checkec the points and they were burnt up so I replaced them and the condenser. It was okay for about 10 miles then it started happening again. I replaced the spark plugs, wires, and double checked the gaping for the points and timing. No luck. So I looked at the carb and it was fullof carbon. I cleaned the barrels up and blew out all the vaccum lines. Now it idles rough and wont rev without dying. The carbon led me to believe maybe one of the piston rings is bad. Ran a compression test and all cylinders are 120 to 135. I dont know if I could have messed something up, or if I just need to tune the carb. If I need to tune it, im not sure which screw is the a/f and which is the secondary, let alone how to tune it right. What should I do next? I atatched pictures of the carb. Onthe first you can see the plastic adjuster screw and there is a secondary screw ust to the left at about east to northeast. Any suggestions?