Hello to everybody, thanks for this intersting forum. A friend of mine gave me her Petromax 826 asking me to have it lighting again. According to the scratches on the bottom and to info on this forum it may be as old as january 1931. My friend bought it in a military surplus vintage shop. It took me some hours to clean it and to free the carburator from very hard and stubborn clogging. Then I lighted it but after few minutes of light (not enough anyway) il turned to simply burning. See pictures. Few questions: which is your diagnosis according your experience ? Which parts should I change ? After pumping and heating with alcool (two "cups") I opened the gas and it worked for few minutes: which is the correct procedure then ? Thanks, I really appreciate your help. Giacomo from Italy Italy
Giacomo Welcome to our hobby. There are many experts here that might offer top advice, but I have a few pointers that you can consider in the meantime. 1. Have you confirmed that the lantern is holding pressure? The NRV (Non Return Valve) situated at the bottom of the pump column or the fuel cap seal are usual suspects because of the age of the pip and seals. Leaks around the control assembly and vaporizer is also possible. A dunk test in water after pressurising will identify leaks. 2. Confirm that the needle cleans the nipple when turning the control wheel. If operating the needle improves the flame, dirty fuel is indicated. Is the fount (tank) and kerosene/paraffin fuel clean? Contaminated fuel will cause clogging. 3. Have you confirmed that the burner nozzle and air tubes are clean? After checking these few things, we can suggest fixes or further faultfinding
Mine did that when it leaked from the thread at the base of the nipple. That only happened when the heat caused some expansion i.e 3-5minutes of running. It just needed tightening. This shot was cleaning needle lifted and the burner assembly heated with a torch.
Thank you Johan and others, your suggestions are very valuable. I assumed that everything’s was clean as I just had gone through overall cleaning but maybe there were still parts and dirt in the tank. Or maybe I have leaks on the line. I’ll check these points and return on the forum. Just one more question: I dismantled and inspected NRV and it looked me it was working. Sorry for asking such a basic question: once the lantern is running do I have to keep pumping to maintain pressure ? I thought it was just a start up procedure in order to bring paraffin to the carburetor and then the burning would “pull” from the tank. How does it work ? Is there a section in the forum I didn’t look at ? Thanks for your time and help. Giacomo
This is a pressure lantern therefore, it requires pressure. You must pump air into the tank, at least 30-40 pumps. I would use a "soft start". Fill the alcohol/spirit cup with denatured alcohol. Light the alcohol and make sure the fuel valve is open. Let the alcohol burn until it's almost gone, then start pumping the lantern. This is the "soft start" procedure. Just take it slowly and pump about 30-40 pumps and it should light if the lantern is working correctly. Make sure the little knob on the tank cap it tight. This should do it! Just take your time.
Yes. When you notice the lamp is not as bright as it was, pump in more air until it burns brightly again. If the pressure gets too low, the lamp may start to burn like in image 3 of your first post. The tank on your 826 will hold 1 litre of paraffin and the advice given by @george is good if you have1 litre of fuel in the lamp. If there is less fuel, you will need to pump in more air to get good pressure, even with 1 ltr. of paraffin, you can give 60 - 70 pumps. Henry.
