Greetings All, New member here but I've been lurking for a while. I need some advanced guidance in tuning my SVEA 123R for best performance. Thanks in advance for your help. My problem: The SVEA that I've used and loved since my father bought it for me in 1975 for my first backpacking trip at age 13. Finally did a rebuild using parts kit from Optimus. After the rebuild the stove runs well but I'm getting orange flame tips rather than the completely blue flame I'm used to. Specifically, and I'll try to describe it as accurately as I can, the flame that is inside the burner is nice and blue but about an inch or more of the flame that extends outside of the burner is orange (no smoke though). This suggests to me a rich mixture but I'm not sure. Additionally, even after burning for about 10 minutes the cap on top of the burner isn't glowing red like I'm used to. Here is what I did during the rebuild (please ask if we need more detailed information to troubleshoot) Replaced the gasket in the filler cap Replaced the spindle according to Optimus instruction sheet Replaced graphite packing on the spindle Replaced the jet Replaced the cleaning needle Removed, inspected and re-installed the wick-it's in fine condition: no charring or noticeable deterioration Leak tested the threaded joints at the fill cap and the vaporizer (no leaks) Filled the stove with new fuel (Coleman red bottle fuel with 2015 date code) Primed the stove by filling fuel bowl with fuel and lighting it. The stove built up good pressure and burned strong but with the orange flames that I described above. I've attached a photo of the stove operating with orange flame visible. Those are my methods and observations but this is the first time I've rebuilt my SVEA, so I lack any in-depth experience. Finally..I currently do not have the cleaning needle installed after reading here to try it without. The flame in the photo is without the cleaning needle installed Thanks again for your helpful replies.
Hi Bill, Welcome to CCS. So, in taking the cleaning needle out you have changed the way that fuel flows in and around the vaporiser / jet / burner bell. There have been several threads on this site where the height and shape of the burner plate affects the flame characteristics. The easy answer would be put the needle back and see if your flame is restored to how it was. You can always take it back out again. Secondly, it's not just the quality of the wick but how tightly and how far it is stuffed into the bottom of the vapourizer. Too tight will restrict the flow rate and therefore reduce the flame. It.s possible that you found the sweet spot when you refitted it. Too much fuel flowing can mean that there is insufficient mixing with air leading to non optimal flame colour. Regards John
First thought. The packing nut doesn't look like it's tightened all the way into the valve. I don't believe this would contribute to yellow flame, but just looks suspicious. Question: is the jet tightened down and giving you a good seal? Did the old jet give you yellow flames? Second thought: your flame plate looks as flat as a pancake. Is it? You may want to look in the gallery to see the shape of the flame plate just to be sure that it is shaped correctly and the height adjusted properly. It should be concave. Third thought: It looks like there is fuel leaking down the burner body and the burner bell looks like it was sitting in some kind of oil. Is there a leak there? Are there carbon or deposits on the inside or outside of the burner that should be cleaned off? A gummed up or carbon filled burner will give you yellow flames because that would keep the fuel from completely vaporizing and give you yellow flame tips. Just some thoughts. sam
https://classiccampstoves.com/threads/svea-123-orange-flame.25789/#post-262389 You could unclip the burner plate, and once the flame is established, grip the flame-plate gently in snipe-nosed pliers, and raise it a mm or so. If the flame becomes bluer it suggests the current mixture is fuel-rich, and you have made it leaner by raising the plate. You could the bend the supports carefully to set tge new higher flame plate position. Alternatively a smaller aperture jet would produce a leaner fuel/air mixture. I actually think your flame pattern is pretty good and once you put a pot or kettle on it the flames will become almost totally blue. Best Regards, Kerophile.
It looks to me that the flame plate is dished upwards far more than would be usual for a 123R and the OP says the jet's been replaced. Besides, Sam's right, there's no dished shape to the flame plate disc. Ball pein hammer, sand bag, bash the disc into a concave bowl shape. Smaller aperture jet Kerophile? It's the 'R' model so there's no option of a smaller jet, unlike the 123 with the 0.23mm or 0.32mm jet orifice variants. This is the flame plate configuration I'd expect for a 123R Try moving the flame plate down. Kerophile's comments about 'pot on board' effect on combustion is true, but as my example of a 123R with no orange tips to the flame illustrates, it should be possible to get correct combustion pot or not. Welcome to CCS by the way!
I agree with presscall, I loosened the tabs on my burner plate and let it just sit on top. Now my Svea burns beautifully.
