Hello, another Petromax 834 lamp has arrived from India. It is a newer version - in the photos you can see a comparison of the early version with the newer version that has the petromax logo used until today. I completely disassembled the lamp, cleaned it and put it back in the pile. What's worst is that I didn't manage to light a single 834. I'm at a loss now, I've tried changing the fuel nozzles in different sizes, unfortunately nothing helps and flames still form around the mantle. The last thing I could think of today that could be bad is the ceramic nozzle I bought on Ebay that was originally intended for a Coleman 150 CP (ebay photo in gallery). Possible? What ceramic nozzle are you using? Many thanks, Dan Bittner, Czech Republic
Well what you don't mention is if there is any fuel coming out of the jet without preheating. I do a cold test with any lantern to see if there is a fuel spray leaving the jet. In fact it should be a straight up or down line of fuel. Having said this flames are from: leakage or not enough preheating. leakage can be form the mantle itself > holes, not attached enough, bad fitting of burner parts. The donut lamps I have all suffered more or less a burned out burner assembly. For the 835 and up you can use the modern genuine petromax parts. For the 834 a 200Hk 250cp version I found that old Graetzin gas lamps can provide parts that fit or can be made to fit. The ceramic burner shown in the ebay ad needs some attention looking at the holes and it says 150cp which is to small. As for dating: I am very reluctant to date any India lantern since they used the lamps and switched all/any parts whenever needed. I have seen pre-heating rings made from alu foil to bated into shape metal strips.
Then the problem will not be in the ceramic nozzle. I made a reduction on the lathe to a large burner and the lamp still makes flames. Most likely it will be the nozzle, tried to install a 0.15 mm nozzle and the same problem. Does anyone know the size of the original nozzle?
I don't see a preheat bowl.You have to mount the preheating bowl and preheat the carburetor. I also have the impression that the burner protrudes way too far down.
I preheated the carburetor using a propane butane burner - preheating with alcohol is the same problem.. The tube is longer due to the use of a reduction from a small porcelain to a large porcelain nozzle. All the same result. I feel the nozzle should be around 0.12mm..
0.12mm is for 100HK (92cp). 834 is a 200 HK (184cp) lamp and the original nozzle would be around 0.15mm. It may be the camera angle but it looks like the nozzle and mixing tube (in red) are not in line. Can you increase the distance (yellow) between the nozzle and the mixing tube ? The slot in the regulator screw (blue) should be vertical.
Without the pre heating bowl your lantern will not operate correct. The 834 is a 200Hk or 250cp lamp. So the 250cp now available part should do the trick. Besides the already mentioned issues. Original jets where made of steel and had a depression on top to guide the cleaning needle (hand operated). Finding those is possible in the far east but then the thread in the vaporizer may not be damaged. This occurs easy when trying to mount a new modern one (which "may" have a different thread).
Hi Dan, For your nozzle, take a 0.16 mm working base, this is the standard for a capacity of 200 cp. Set up an effective preheating. A ceramic nozzle for the Optimus 200 cp type should do the trick. Take the greatest care in adjusting the air intake which should be approximately 11 to 12 mm between the top and the nozzle and the inlet of the mixing tube, this is adjusted by doing many tests until to find the right ditsance with first-fresh kerosene. The nozzle holder is much too long. Indeed it is very complicated to find unmodified lamps in India. I wish you good luck. You are at the heart of the passion, you will end up being rewarded with a beautiful light. Above all, don't be discouraged, if necessary, take a break from this and win. Best regards, Titoo.
The pre heating disc is not only for pre heating but will also create a specific air flow for as well cooling as keeping the vaporiser heated. As far as I know there is no adjustment in height above the jet. The complete mixing J-tube is one piece and mounted on the cast iron base plate.
Thank you all for the advice, I will try to support the "J" pipe so that there is more air in the mixture and maybe it will work. I will inform about the result. Many thanks!
Both of my petromax 834 lamps have original parts and nothing is missing, no part has been repaired. Only the nozzles were corroded and full of dirt and the ceramic nozzles were missing. I made a reducer for the nozzles from a gas stove (I have sizes 0.1mm, 0.15mm, 0.20mm available), Unfortunately, they are taller than the original with the reducer, so I will try to fit washers under the original "J" pipe.
I wonder why then you show pictures of the lamp without the pre heating ring? That is an essential part of the lamp. As for the burner head and ceramic nozzle: you may try the standard 250cp assembly. Available for the 250cp lanterns. any brand will do the trick. For the jet I would go for, again, what is available new in 250cp. original they where made of hardened steel trying to save those is a challenge.
I didn't know the lamps didn't work without the ring. Of course, I have rings for both lamps. Where can I buy a 250CP porcelain nozzle that will fit the same thread?
Hello, many thanks to everyone who gave me advice! Today it worked and one of my newer Petromax 834s finally lit up. It worked after adding washers under the "J" pipe, I fitted the lamp with a 0.15 mm nozzle for "MEVA" gas stoves (they have an external cone for cleaning) and a made reducer on a lathe. I am happy, thanks thanks thanks!
Simple answer - because the ordinary Petromax nozzle does not have a cleaning cone on the outside + it cannot be bought here in the Czech Republic. The nozzle I used is universal for gas heaters and stoves, comes in many sizes and costs less than a dollar apiece and has an outside cone for cleaning. I am able to make a reduction on a lathe and choose different sizes of nozzles (I have 0.10 ; 0.15 ; 0.18 ; 0.20 ; 0.23 mm available)
