The effects of the concentration and the pressure of reactants on laser output were reported in the previous study. The present study is made of the following main parameters on laser characteristics; the initial temperature of the reaction mixture, inert gas (He) added in the reaction mixture, and the level of initiation as a function of time. As the initial temperature of reaction mixture decreases, both the output energy and the duration time increase. Especially, the output energy is linearly proportional to the inverse of the initial temperature. In order to obtain a proper lasing for a given condition, a sufficient amount of He must be added: The optimum ratio of [He] to $[D_2;+;F_2;+;CO_2]$ is found to be greater than 2. In addition, the time dependence of level of initiation (TDLI) shows no significant difference in total output energy from that of the premixed model, but only the power profile.