Allen 221 Hover Mower with Tecumseh 5hp Engine Carb issues

Hi all I have an Allen 221 Hover mower with the Tecumseh 5hp engine TVXL-840A and it just won't run..I have a good spark the carb has been stripped it's a Series 6 carb and cleaned the primer bulb is in good condition but will not prime I have soaked the carb in cleaner and blown through all openings...when I use engine start in the air filter it will start and run for approx 2 seconds then dies.. The carb must be some kind of special because of the hundreds available on well known auction sites non are the series 6 part number 632434 they are showing on the repair clinic web site item number 1727806 but unavailable anywhere..any help would be very much welcome and have to say what a great forum of information...