[RICK LAKE]

Gun Doc If the spark plug is wet, I would n't start with the carbs. Start with the cap and rotor on the MSD. REPLACE both. MSD has had cap failures and burnt holes in the rotors. Make sure you have good light in that cylinder.
Next You may have to do a little search on this forum and the FE forum but running Platinum plugs is no good for MSD systems. Running just 3924 with a wider gap of .044" Is what I believe is to be run with stock plugs.
As Gaz said the easy thing is to swap carbs and retest. If you have poping and back fires, this is more ignition than carb. Get a spark tester and make sure you have a good large blue or yellow spark. If not the coil could be going. Lets try the basics first, Check for good spark in all cylinders and see if you can shoot a picture of inside the cap and rotor. Rick L.