I have a BernzOmatic TX-550 Gassie stove with a yellow flame issue. It burns nice and blue on very low settings but when turned up even slightly, it starts to burn more yellow. I verified that the internal burner passageways aren't blocked and the jet is clean and clear. The burner didn't have any kind of an inner cap in it when I took it apart to clean it. Borrowing an idea from liquid stove silent burner design and before I did anything permanent, I tried making an inner burner cap from an automotive freeze/core plug to see if it made any difference. It didn't seem to, it may be too small in diameter and too short to be of much help. I noticed the fuel inlet fitting has 2 .187 holes located near the jet outlet 180 degrees apart to mix air with the gas for combustion. The jet is visible through one of the holes and is located on the end of the supply line. When I plug one of these air holes with my finger the flame goes mostly yellow right away. It seems like it's starving for air. The various Bernzomatic propane hand torches I have with the same style valve all have 4 air holes in them of the same .187 size. I'm thinking of drilling 2 more holes at 90 degrees to the existing holes in the manifold to let in more air to aid combustion. What do you folks think? Is there such a thing as possibly too much air?
There is, the symptom of which would be blue flames lifting off the burner and extinguishing. You’re on the right lines, and I’ve modified at least one gassie for more output by enlarging the air inlet holes and installing a jet with a larger jet orifice. New jet on left. Enlarged air inlet holes, component on the right. The question of course is why the stock components should result in the yellow flames. The only wear component is the jet and if the jet orifice has become enlarged (worn) you’d get the yellow flames. Another possibility is a jet that’s loose in the housing for it, or that has worn threads. Gas escaping there will burn yellow. Some gassies I have have a thin lead washer to seal jet to stove. Others use plumber’s teflon tape. As a final resort, maybe drill another air inlet hole (just one initially) to see if it improves matters.
Thanks for your reply @presscall, I was hoping you would weigh in on this. While the flames don't lift off or extinguish, they do seem to be concentrated on the lower rows of holes in the burner. This may be an optical illusion. It's one reason I tried the inconclusive inner burner cap experiment. I've verified that the jet is tight in it's holder, it is sealed with an O-ring that looks to be in good shape with no visible damage. I haven't been able to find much information on this stove online, specifically about the jet and what size it is or should be. It doesn't appear to be marked or numbered, I'm hoping it's not worn out and is up to snuff. I decided to try the jet out of one of my BernzOmatic torches on the right in this picture. A different design but common threads. The torch orifice(left side) is so small I couldn't see it with my corrected vision eyes. Nothing to lose but my eyebrows..... It was a little louder and sounded more like a Coleman liquid fuel burner does. It had a more even flame pattern but it wasn't burning 360 degrees around the burn ring and would not increase in power with more fuel input. Almost like this jet wouldn't pass enough fuel to increase the burner output. The manufacturer completely changed the design of the burner and fuel supply on the later deluxe TX-550L versions of this stove to a more robust design(my opinion) along with a few other improvements. Could it be from feedback on this design, it's hard to say. There is also at least one other version of this same design burner with a cloth covered fuel line I found in the SRG(thanks @Daryl). I'm not sure if it was earlier or later than this version. Short of drilling another air hole(s), I'm out of ideas. If I do decide to drill, it will be one at a time and undersized to start out.
Two quick thoughts for you...In the picture above it look like ORANGE flame, which is often just burning off corrosion and will go away in time. Yellow flame, like you got by plugging air hole, is too rich. On Prentiss Wabers and AGM stoves with those little holes in burner ring, I take a straightened fish hook and gently reem debris out of all those hole. Tedious. Often makes a huge difference.
Thanks for the reply @Majicwrench, The flames look more yellow to the naked eye than it shows in the picture. You can smell the unburned/partially burned fuel when it's turned up higher. I noticed it first when I used a Coleman oven on it during pre-warm. I thought maybe the oven fit so well on it might have been blocking some of the combustion air(I had some foil in the bottom partially blocking the 4 case air supply holes). That turned out not to be the case. Even when initially burning all blue at a lower setting it will eventually start to start to show some yellow. There is some slight corrosion on the inside of the burner ring on one side but it's not enough to close any of the holes significantly. I'm going to take you up on your advise though later today and try to uniform those holes in the burner ring first before I drill any additional air holes in the manifold. It's cooling down right now after making lunch
After cleaning up the burner ring, I couldn't see any change in the flame pattern. I looked for jets online for a few days, all I could find was what were advertised as High Altitude jets and I don't live at altitude. I contacted Bernzomatic for a possible replacement jet not expecting too much(they haven't actually been owned by Bernzomatic since 1982, the Bernzomatic name is currently owned by Worthington). They did get back to me and surprise, no luck. I saw a J.C. Higgins 2 burner stove locally awhile back that uses the same style burners and fuel supply manifolds so I kept an eye on it. I grabbed it yesterday on speculation and for ready spares if nothing else. These stoves were manufactured under the same Patent numbers as the Bernzomatics were and look identical except for the name on the decals and instructions. What's one more stove in the name of science..... Ironically, two Worthington propane cylinders came with the stove. After doing some more research, it appears this J.C. Higgins stove has High Altitude style Jets installed. They are a bit different but share the same threads. Neither are marked except for 2 sets of grooves on the hex of the standard jet. High Altitude style jet on the right. One of the supply manifolds the stove came with leaked at the control valve shaft(hopefully it just needs an o-ring) and also had a clogged jet, I set it aside. The second manifold didn't leak and the jet was clear so I plugged it into the TX-550 single burner stove for a test fire. The flame was much more defined and crisp and used the whole burner ring but this was as big as the flame would get, better but not right yet. I think the High Altitude style jet may be holding the stove back a little bit at higher settings at basically sea level but it sure does simmer better this way. Lol As near as I can tell, the standard jet opening should be .008 but I have no real way to measure that small of a hole in the jet I have other than visually, it looks quite a bit bigger compared to the other jet. After comparing the different flame patterns, I came to the conclusion my original jet has been worn oversize. I need something in between the two jets I have. After reading up here about the process, I'm going to attempt a jet repair with a hypodermic needle on my original jet, a 27 gauge needle has a .008 inner diameter and a .016 outer diameter. Hopefully the hole in the jet isn't larger than that. I've done some soldering in the past but have never silver soldered anything so it will be a learning experience for me. Any insight will be greatly appreciated.
@Oldhenry1 You may not need to silver solder the needle insert in place. Early on in the repair method using a hypodermic needle to repair jets/vapourisers that @Doug L and I devised, I made use of an interference fit of needle insert and jet, as HERE.
Thanks @presscall I've used a method like that before on automotive parts. I'm hoping there is enough interference left in the jet to fit it in this manner that the silbrazing part isn't necessary. More to come.
