Hi all, I bought a really nice Optimus 1200 lamp a few days ago and I was looking at it today after it arrived in the post. I was reading on this website, just to give me some basic ideas on how the lamp should be to get it functional. The previous person who owned it took it apart and clean the lamp really well but it looks like they just put it back together and took the photos to sell. The gap between the fuel nipple and the mixing valve was 17mm and I changed it to 12mm (as I read on this site was the Correct gap). I Put kerosene in the tank and I had The top removed off so I could see what was happening. When I added pressure on the fuel. The needle drops down and fuel squirts from the nipple as designed but the fuel never makes it around the U bend on the mixing valve, instead it hits the open/close little bar inside the mixing valve. The valve is opened (the adjusting screw head is vertical so I can see it is opened without looking in) and the fuel hits the little bar inside and pours down the side of the lamp and goes everywhere except to we’re the mantle would be placed. Can someone tell me what I am doing wrong. The nipple is a 250cp so that is correct, the mantles are original 200cp, and the ceramic part is also 250 cp, that the mantle ties on to. I have all original spare parts. But Why does the fuel hit the open close bar inside the mixing valve? Is that how it is meant to be? And if so how do I stop the fuel leaking everywhere. Sorry for the long message.
Hi @Liam! We love pictures to see how it look. Sound like You didn’t preheat with meths (Rödsprit) before so the kerosene is to cold. What Do You mean with ”But Why does the fuel hit the open close bar inside the mixing valve?”? Regards Matti
When heated to operating temperature the fuel comes out as vapour and mixes with air in this open chamber. The gas mix travels out the ceramic nozzles before burning in the mantle. Sounds like everything is OK
Hi matti I did preheat the lantern and I also installed a new mantle and burned it off first, let it cool for a bit then reheated it again ( it was so hot I couldn’t touch the top of the lamp, I tried ha ha.
Why can’t understand is why does a river of kerosene flow down from the nipple area, I have tried turning it on a little to see does the kerosene make it around the bend in the mixing valve nut on high Or low with the on off knob fuel does pours down the side
Aaa ok. Another thing is I was indoors and I was trying to light it with the glass removed, would that of caused a problem? It has frosted glass and I couldn’t see what was going in inside.
Hi matty I forgot to answer your question, the fuel jets out the nipple as liquid and not vapour as from what I was just told it should and the jet of fuel hits the little open close bar inside the mixing valve, I hope you understand what I’m trying to explain.
The jet of fuel from the nipple hits the little bar on the inside of the mixing valve and pours down the side everywhere. (Used someone else’s pic just to explain) But when it gets extremely hot the nipple releases Vapour and not liquid? Sorry for the questions.
Hi Liam and welcome! As folks have said there should not be any liquid fuel coming out of the jet once you have preheated with meths You may find you need to preheat twice? If you are indoors with the glass off the lantern make sure you have safety precautions and also fresh air but at the same time the flames must not be in a draught? Not easy with the glass removed and the door open ! ps when all is hot and the fuel exits as a vapour it will mix with the air and flow past the mixing paddle, (you can’t see it!) up and around the u bend to the nozzle and mantle, on the 2nd pre heat don’t let the flames die down too far before you open the valve?
hi and thanks for the info, to be honest there was a strong draft and it was blowing the meths flame about. I’m happy that I know what was the issue and I am buying Original clear glass so I can see inside, I should have it in a few days so it will be a lot easier to light. I will put up a photograph of the lamp lighting in the next few days. I hope ha ha. Thanks all.
That is a nice looking lantern and always good to have a spare glass as well I’m sure you will sort things out and we’d love to see the lamp ‘in action’ Best wishes
Hi @Liam! I cannot say for sure, but the J-tubes on the 1200 I have enqountered hadn’t any adjustment bar. Make sure it is set as in the picture. What do You say about this @Nils Stephenson?
For kerosene to be ejected out from the jet as invisible vapour, the upper part of the vaporizer has to be at least, close to or in the region of 300°C. Make sure the spirit flames are thoroughly licking the vaporizer during preheat. Put some barrier around your lantern to prevent wind/drafts if you need to remove the glass globe to see what's going on.
This is the last variation of the 1200M and was produced in the (late?) 1980s and possibly 1990s. They were made with parts bought in from Hipolito which is why many of the burner parts look more like Petromax than the earlier Optimus parts. The inner top was one of the parts bought in and therefore has the adjustment paddle in the J tube (mixing tube). As has been said several times before, there should not be liquid fuel coming out of the jet. If there is, then it is not hot enough. This lamp came originally with the fully frosted glass, but I agree with you that it is annoying that you can't see what is going on when pre-heating.
Thank you all, I know and understand a lot more now about the lantern, thanks to yourselves. Have a good weekend and I will post a picture as soon as I get a chance to try light it.
Hi Liam here, a quick question, which Optimus lanterns are the rarest. And more collectible? I’m getting hooked on lanterns and my wife drags me to old auction houses and markets here in sweden. So if I see one’s that are the most collectible, I would know to try get it.
I don't which one is the rarest Optimus but the Optimus 500 and Optimus-Lux-Sirius might be uncommon enough.
@Liam Have a look at the Reference Gallery, if there are not many examples of a model then it indicates they are hard to find. Good hunting.
Hi all, I spent the last week trying to understand the lantern and it pushed me to boiling point, at times. I got the lamp lighting and it looks great, then it would flame out big time from the mantle area then the top of the lamp. So I removed the top of the lamp so I could see the jet ( so I could see was there something making this happen) and when I preheat the lantern (twice) then build up the pressure and turn the knob to start lighting the lantern, I see vapour coming from the jet, so perfect, and it lights up beautifully but then after 2-3 min the jet stops spraying vapour and instead jets liquid. Then the flames start coming from the mantle then spread to the top of the lamp. I had a think, and only one thing can make this happen, temperature is dropping inside the mantle area. The mistake I was making was I was not opening the knob fully to allow the mantle to burn at high heat. I thought by turning the knob down and controlling the fuel, it would stop the flames. Instead It was stopping the lantern from burning at high heat and producing vapour from the mantle. What I wrote is probably pointless to many but It might help someone new to lanterns.
Hi Liam - glad you got there. Like a lot of things in life once you know it all gets simpler ! - The knob as you now know is not a brightness control. Many people have fallen into that trap - and I can understand why. It is a lovley old lantern and a real treasure - even better when it is working
Yes for sure. And the reason I heated twice was it was 0 degrees out so I had to help the little lantern. Ha ha
