"" I'm running an orange accelerator pump cam/.035 squirter"
- The ORANGE cam is the second largest 30cc pump cam. It is very aggressive off idle and "could" cause the black smoke at the blip of the throttle. Try using a less aggressive pump cam (white/black).

Check your power valve as noted. My NEW 10.5 QF power valve was bad and QF is who told me to check it!!
Double check that you tightened down the IFR's. If they are not tight, the fuel would leak past them. I know that they are small but just make sure that they are snugged up.

I am still guessing that "something" is leaking on you that is causing the fouled plugs since you have seen this since running the .025 IFR's. You have found that .025 & .028 IFR's are too lean, so maybe the .030's might help out a bit.