I have a 53 Jubilee/NAA that I have had about 8 years. I have cleaned and rebuitl the carb a few years ago. Recently it sat for a whiel so I disassembled the carb, chased all the apertures with fishing line, spryaed it w carb cleaner, check float, etc.
Oddly, when setting the main jet, I cannot ever seem to make it too rich. Start 1 1/2 tursn out, tracctor strats; about 3/4 turn in and it stumbles. I can back it out out out until its loose and the tractor is still not too rich.
Any idea? It seems to run ok.