I lit my italian Petroflam lantern (200 hk) for the very first time. For the first few minutes, the burn seemed perfect: the mantle was bright, the pressure just right, and the light strong. After a while, however, the flame began to change colour, turning slightly green, the light grew colder, and the mantle darkened. Does anyone know what might be causing this?
There are several faults which can cause that problem, the vapouriser may have a lot of carbon in it, the pricker rod may be coated with carbon, if the inside of the tank had dirt in it or old residue sticking to the tank it then loosens when fresh paraffin / kerosene is put into the tank and that dirt will affect the flow of the fuel and air, the vapouriser's jet may be loose, the ceramic burner nozzle may be loose.
I assume this is a continuation from your earlier thread on this Petroflam. The lantern cannot be regulated in the correct sense. It should only run at full blast with whatever pressure driving it. There is no valve at all. The needle should not be used as any kind of regulator under normal conditions. It usually won't shut off the fuel flow. During operation, it should be retracted all the way down. Check that everything is tight as suggested by Jeff. No loosened or misaligned parts including the J-mixer tube before the burner. This affects mixing and fuel-air delivery to the burner. Also flush and drain all the fuel and recheck that it remains clean and clear with no suspended particles that could possibly block the fuel path. If all assembled features seem fine yet the symptom persists, then you might need to consider stripping it down again for further work including thorough cleaning of everything, particularly the vaporizer. Before that, ensure you have sufficient spare mantles at hand. If you decide to strip and restart all over, then you should also attempt to test run it without the mantle attached. It should burn with a clean, pale blue flame if working correctly. If it turns yellow in anyway, then the burn isn't correct. During mantle-less test, there should not be any gusts of wind or draft to affect the flame. Otherwise, it won't heat vaporizer sufficiently to gassify the fuel. The gap between the jet or gas tip and the J-tube's inlet should be approximately 12.2mm +/-0.2mm for a 200/250cp lantern, but this can be varied to optimise whatever suits your particular unit best.
I have the impression that the mantle isn't inflated properly. The pressure in the pressure vessel is too low,and the small residual pressure dissipates quickly.You need to do a proper pressure test in the water bucket and locate the leaks.
