The ram-wave spectra of 14Na~SFa in the excited vibrational states v5 = 1 and v6 = 1 have been recorded. Analyses of these have yielded values for the Av rotational constants and hence a better determined structure. In addition the coriolis constants g55z=-0.2256 (18) and g66z=0.1569 (15) have been obtained, These have been combined with accurate measurements of the centrifugal distortion constants of the ground state, some isotopic vibrational data and ~e6z=0.1657 (15) for 14Na4SFa to give a good estimate of the most general valence force field.