Hello. I am new to this forum, but have some questions regarding the Optimus 930, 300 cp version. "Vintage" kerosene, is somewhat hard to come by in small amounts, so I tested my lamp with plain supermarket "lamp oil" and it lights up just fine, but after a short time, the mixingtube begins to glow, the light dulls a little and dark spots begins to emerge on the mantle, as well as flames on the outside. The pressure seems fine, though I have no way to test it, other than the release valve gives proof of healthy pressure in the tank, after I extinguish the light. The cleaning needle in the nozzle, works just fine. I have read about the so called Optimus problem, that is similar to mine, and there is a lot of hocus pocus and snake oil advices around, that confuses me a little. 1) If I take the lamp apart, will I need new washers or other stuff ? 2)How do I proceed, troubleshooting the lamp, do I need to change parts until the problem dissapears, or is there a way to find out exactly what parts ? 3) Is plain old kerosine the best fuel ? Any advice, as to nozzle and mantlesizes other than standard is welcome. Other ideas and advices are also wary welcome. Cheers from Michael. Copenhagen.