Calculations of ion partitioning in the hot outer Io torus have failed to account for certain observed features. Notably, the low concentration of OIII measured in the first half of 1981 has been difficult to reconcile with abundances of other ions inferred from Voyager 1 and 2 measurements in 1979. One possible explanation invokes a two-state plasma torus and suggests time-dependent changes of bulk composition. In this paper we propose an alternative time-independent model (time-independent in a mean-value sense) but introduce the ratio of sulfur to oxygen in the neutral source as a free parameter. The recent evidence that there exist distinct sources of S2 and SO2 justifies this introduction of independent sources of S and O. In our calculations, we also varied the relative abundances of hot (1 keV) and thermal electrons, the neutral injection rate and characteristic radial diffusion time scale, and the characteristic ion temperatures. We integrated the rate equations over time until a steady state was achieved. For a pure SO2 source, we found no solutions qualitatively compatible with observations. A solution in qualitative agreement with observations emerges when the injection rate of neutral S2 is about 60% the rate of SO2. The deficiency of OIII observed in 1981 is obtained in a model consistent with other aspects of composition and dynamical features of the torus observed in 1979 at the time of the Voyager encounter by including of order 0.05% of 1 keV electrons and using a radial diffusion time of order 35 days. The intensity of EUV spectral lines attributed to OII and OIII can be produced by our sulfur-rich torus model if collision strengths of lines near 833 ¿ are taken near the upper limit of their range of uncertainty.