Hi, having trouble on one of my Optimus 96 with high yellow flames after a few minutes and read about the lipstick burner problems on the Optimus 96 I compared with the other one and found out that the burner cap was lower on the one giving problems. I lifted the burner cap using a smal copper ring but the result was the same, high yellow flames after a few minutes. I know the size of the nozzle might have become too big during the years, but could the state of the copper gauze be a cause as well? Or the amount of copper gauze? Regards, Ton.
I would suspect your first assumption that the jet is worn. They are a small stove and get pretty warm in use which will increase pressure as it gets hotter. Try more pump strokes at the start and see if you can recreate the effect from cold. 20+ should do it.
Hi Simes, it is not that sort of yellow flame I am talking about. It seems the stove stops vaporizing after having started normal, during the last warming up I close the valve on the tanklock, give three pumps and when the warming up fluid is gone it burns normally. Some five pumps more and it burns perfectly until after a few minutes it stops vaporizing and begins spraying a mist of fluid giving a yellow flame , about 10 cm high. When I lower the pressure it begins burning normal again for a while until the problem repeats. I thought about a few things to call, the lead ring, mine has a copper ring between burner and tank and it is tight, that should do it? Then the gauze, does a lipstick burner need one in order to burn properly? And how tight should that be? And the amount of fuel in the tank, could that be a course? I know, easy to call. Regards, Ton.
Hi Ton, without the gauze the burner will do exactly what you just described! It is also best to replace the copper ring with a lead one. It takes a fraction of the force to tighten up a lead washer vs a copper one. You might damage the stove by using the copper one. Do you have the old piece of gauze? It can be cleaned and used again. Groetjes, Wim @ton visser
Good morning Wim, the gauze that is in gives the impression to be home made. Should the gauze be as tight as possible and should the whole lipstick burner be filled? And is there any alternative material that does the job? Regards , Ton
Ton The gauze often looks homemade, but it’s essential for the smooth operation of your stove. If you do not have brass gauze to replace it, get the old one, unroll it, and burn off the carbon with a blow torch (be careful not to burn a hole in the gauze). Then roll it back up, not too tight, and put it back in the fuel line. The gauze helps the vaporisation of the fuel. The tank should be no more than 3/4 full. Don’t pump hard until the burner is hot; don’t overpump. Cheers Tony @ton visser
@ton visser, a quick search for the term 'gauze' threw up this thread which may help. https://classiccampstoves.com/threa...or-no-96-and-no-100-stoves.28557/#post-291322 @kerophile Try cleaning the gauze first as described also the inside of the lipstick. If you're happy with the performance just after priming then the jet aperture sounds good. It may be worth checking to see if you can get a .32 pricker down it, in which case it's worn. Either peening with the correct pricker in place or fit the hypodermic.
Here is an image of various meshes used. The original one in the middle. The orifice of the jet is supposed to be .23mm, so as Simes said it is a good idea to verify opening with a larger pricker. Make sure you have maximum heat transfer from the bell to the lipstick by cleaning the surfaces (you raising the bell may worsen that).
