In Part I the problem of low-frequency combust ion in stability in monopropellant rocket motors has been analyzed under the basic assumpt ion that the t ime lag is affected by pressure variations. The same idea is applied now to the bipropellant case. It is shown that for certain relations between the parameters of the two feeding systems, the results of Part I on monopropellant systems can be rigorously applied. The effect of varying the parameters from these values is also examined. A brief discussion is given of a secondary effect neglected in Part I, applicable to both monopropellant and bipropellant cases. Finally, using a simplified model for the spatial distribution of the combustion in the chamber, the case of high-frequency instability is analyzed. The correlation between unstable and natural frequencies is shown, and the ranges of the t ime lag in which high-frequency modes become unstable are found. The generalization of the results to real models is discussed.