I have an old Optimus stove that appear to have never been used. It is clearly marked kerosene. The kerosene that was in it has apparently degraded and does not light. Can I use Coleman stove gas in it safely or does it have to be kerosene? From reading the archived articles I assuming that the ring under the burner needs to be filled with gas to preheat the burner. I will use stove outside in cockpit as the cabin ceiling is lined with carpet. I don't want to catch it on fire or turn it black with soot. Frank