Not trying to be picky, but it's worth knowing that the screw you found is not an air bleed, it is a low speed needle. The low speed needle adjusts like the main needle; screwing it in leans it out, screwing it out richens it. An air bleed works the opposite way, because screwing it out will let more air in, which leans it out.

Your Saito does not have an air bleed, it has a two needle carb. But some engines do have air bleed carbs so it's good to know the difference.

Jim