I'm dealing with the same problem. Removing the AI reduced the popping by about half. I can live with it now, but still way too much unwanted noise. Hate the popping. I bought 130 main jets but have not installed them yet. The idle mix screws are out to about 3 1/2 turns. Also have not sync'd the carbs, but need to, as the it seems most of the popping is from the left cylinder. Keep in mind Triumph desires our bikes to run ultra lean. Just because THEY don't feel re-jetting is needed, doesn't mean it ain't so!
