hello all.just purchased a 1966 3000 mk3. not running and having carb issues. This is my second 3000 having one 25 years ago but sold due to outriggers rusting and at the time could not afford repair. A few people have messed with the carbs and I got a rebuild kit(Moss) and things were going well until final stages saw that the piston is free until air horn is 1/8 to 1/4 attached then seems to bind. Lifting air horn ever so slightly drops the piston almost seems like a vacuum. Gonna order new springs and if that doesn't hlpl may need a referral to a rebuilder. Any ideas?