My Swedish sailboat included an Optimus 535A in excellent condition - the stove worked really well, but I prefer the use of kerosene. So I purchased the regulating burners along with a massive number of spares from www.tilleylampsandstoves.com At the moment I'm having an issue with my burners acting erratically. I pre-heat with alcohol and all seems good initially, but after they reach a particular heat they (one more than the other) begin exhibiting the behavior in this video: Sometimes it will flicker and reignite (first event in the video), other times it will remain in the state seen until the video ends. If I turn off the burner and reignite the cycle starts over. I'm taking this stove with me on an intended circumnavigation so I'm hoping to have both burners running smoothly and reliably.
I've done a significant amount of troubleshooting - this is possible given that I have so many spares available. Some of what I did: Rebuilt the regulator/repacked graphite (I did this because the burner wasn't entirely extinguishing as well) Replaced the jet Removed the cleaning needle Cleaned out the chamber of the burner w/ compressed air Replaced the burner caps I may have just now found the solution. I believe the issue may have to do with the burner caps not sealing well at their base, or being generally loose. The Tilley burners are not constructed with very tight tolerances, so the base of the caps and the pan do not seat well. I was not aware that this was a significant requirement for proper operation, but after tamping them down some it seems to have alleviated the symptoms - and since bending the tabs so that the caps can't move at all, the issue appears to be entirely gone. Previously slight movement or tapping would cause the burner to flicker as seen in the video. Now that behavior appears gone. So there you have it. If any odd behavior returns, I'll report back.
@AmericanVagrant That is called underburn, and it can ruin your outer caps (really). It happens when the flame is coming directly from the jet(nipple) and from under the caps of the burner. That can be a partially blocked jet or a wrong seated outer cap (allowing the combustion inside the cap). You did it well sitting the caps smoothly and firmly with no clearance with the burner. Anyway, pay attention to the sound, avoid the underburning because it can destroy your outer caps, really.- Regards Enrique
if these are standard burners with an alcohol jet, have you tried using a restrictor tube in the burner?
Very nice video showing a burner in an underburn condition where the flame is inside the cap and making the associated rumbling sound. Seems you've diagnosed it correctly with the outer cap being the culprit. I don't have this particular model burner but good fitting caps are a necessity. If the problem returns you'll have to look for a better fitting cap set. The inner cap ideally should be the same height as the central burner tube and the outer should be a good fit. This same seller you've linked to has NOS British Mil SH&H brass caps that work well for me and offer the same tight fit as the Swedish stove makers original brass caps. I would ask before purchasing but maybe they will fit your burner.
Thanks for the tips - much appreciated. shueilung.2008: I can see how it would ruin them. The burner caps would get red hot on certain occasions. theyellowdog: They're the reproduction kerosene burners (these ones: https://www.tilleylampsandstoves.com/product-page/primus-stove-regulating-burner). I've removed the original alcohol assemblies. Ray123: Good to know, if the issue comes back I'll first try the original burner caps off the alcohol burners. Failing that, I'll see about the NOS ones you speak of.
@AmericanVagrant you probably have solved the problem, but these tubes might also help... https://classiccampstoves.com/threads/111t-restrictors.8823/
American Vagrant you would not happen to be a certain buy who works for a certain beer company who just bought a boat and is restoring said boat? A scout solute if it is.
I wonder about the outer cap having too small holes or not enough. It could be possible that the holes are not big enough to allow the air/fuel mixture out quickly enough to burn away from the cap wall. The mixture induction is greater than the ability for the gas to escape from the burner cap holes. It seems to me that the mixture is building up under the cap(flooding) and then spilling out from under the intake pipe that goes through the center of the burner, then going up to be ignited by the small flames pinnacles that are present under the burner skirt(bell) at the skirt(bell) holes, causing a back flash that is causing the under burning problem. If you have some other outer caps that have bigger or more holes than what you have now; it would be worth trying them to see if it improves the way your burners are operating. I also notice that the cap shown has a flange at its base that could be going over the burner bell holes and leaking gas down through those holes and igniting causing a back flash. If you have a cap that does not have the flange and sits tight at the base against the vapor chamber it could solve your problem. Hope that helps, John
Whelp, the problem came back and my fiddling didn't fix it. After a couple hours troubleshooting I decided to just bite the bullet and replace them with some Hanse burners. I'm sure that I could have figured a way to make them work but considering how much I have invested in my trip, I just want it to be right at this point. I haven't had an opportunity to install the new Hanse burners but wow do they look nice! Thanks for that! Not me but sounds like a similar situation Very nice John, thank you for such thoughtful advice
