Hello. I bought the Optimus Nova and used it one time, it worked fine and I used it to cook something. Then the next day I tried to fire it up again and no amount of pre-heating would get the flame to turn blue etc. It just shoots a pillar of gasoline into the sky, one straight line (not a mist). I tried all the troubleshooting things in the manual such as cleaning the nozzle, proper pre-heating, etc. I am pretty sure the fuel bottle is building pressure because there is resistance after 20-30 pumps. I have only used gasoline in it and nothing else.