Brian, yes you are correct when looking at Mk 1 concentric's, but the original side bowl carb's only blowing compressed air through might get a result, as using fine wire will do nothing. To get to the actual fuel pilot jet you need to remove the jet block itself from the main body of the carb........It may come to that if nothing else works.......This is very common on the 229/289 carbs.......either the pilot jet passageway is too small or there can be swarf restricting the same passage.........I have removed the actual fuel pilot jets from newish 36 mm round slide Mikuni's........You could see light passing through the jet, but it had a tiny membrane of dried out fuel across it.......It would not shift with compressed air, and required my using my tapered jet drills to clear the buggers.........These were off a late model Goddet Egli 1330.