We report preliminary measurements of the branching fractions of the decays $\tau^-$ ($n = 0,1,2,3$) and $\tau^-$ ($n = 3,4$), excluding the contributions that proceed through the decay of intermediate $K^0$ and $\eta$ mesons. The measurements are based on a data sample of 435 million \mtau pairs produced in \epem collisions at and near the $\Upsilon(4S)$ peak and collected with the \babar detector in 1999--2008. The measured branching fractions are ${\cal B}(\tau^-\to K^- \nu_\tau) = (7.174 \pm 0.033 \pm 0.213)\times 10^{-3}$, ${\cal B}(\tau^-\to K^- \pi^0 \nu_\tau) = (5.054 \pm 0.021 \pm 0.148) \times 10^{-3}$, ${\cal B}(\tau^-\to K^- 2\pi^0 \nu_\tau) = (6.151 \pm 0.117 \pm 0.338) \times 10^{-4}$, ${\cal B}(\tau^-\to K^- 3\pi^0 \nu_\tau) = (1.246 \pm 0.164 \pm 0.238) \times 10^{-4}$, ${\cal B}(\tau^-\to \pi^- 3\pi^0 \nu_\tau) = (1.168 \pm 0.006 \pm 0.038) \times 10^{-2}$, ${\cal B}(\tau^-\to \pi^- 4\pi^0 \nu_\tau) = (9.020 \pm 0.400 \pm 0.652) \times 10^{-4}$, where the first uncertainty is statistical and the second one systematic.