Hello all. I'm hoping someone can help diagnose this problem. I recently began fiddling with an old Svea 123 (NOT a 123R). This is a 70s or possbly 60s-era stove. The tank had old fuel in it -- possibly 30-year-old fuel. I dumped this, replaced with new Coleman fuel, primed and lit. The burner produced a small, blue-yellow flame. Not a jet of flame, just a tiny flame like a candle, only smaller. The first few lightings, this flame would burn indefinitely, but the stove would never heat up and really burn the way it is supposed to. I tried pricking the jet with the included needle tool, but this did not change anything. Took the burner nozzle out of the stove, drained tank, sprayed tank and burner with some carb cleaner. The wick appears to be OK, just very slightly brown at the upper end. Refueled. Primed. Burner would then light, but again, only the tiny flame. Now the flame would go out after a few seconds. Disassembled again, unscrewed regulator, removed and cleaned. The graphite packing appears to be in place and pretty solid, but I wouldn't really know. Reassembled, filled, primed. Burner now won't light at all. Note, during all the priming, I did not develop a loose flame or jet from the fuel cap. I believe the fuel cap gasket is still good, though I intend to replace in just in case. The tank is developing at least some pressure. I know this, because after the last prime, I tried unscrewing the fill cap while the tank was still warm. It hissed as it let off the extra pressure. So, my questions: -- Any diagnoses for the low-flame issue as described? -- This is an original 123, not an R. All I can find only for refurbishment kits is a 123R kit. Will some of the parts for this kit work in my stove? I suspect the fuel cap gasket is fine, but the regulator pieces appear to be different and I read in a forum somewhere that the graphite packing is not the same size. Sorry to post a new question about a stove that has been discussed extensively here, but I could not find a post describing this particular situation. Thanks in advance.
Greetings, Welcome to CCS. Just time for a short note. I would replace the fuel cap gasket on your old SVEA 123 with a new one made of Viton, or Nitrile rubber. You should get plenty of pressure after doing that. Good luck, and God Bless! Every Good Wish, doc
if your getting a hiss then you have tank pressure.i would guess it's just a matter of 30 years worth of crud in the works.try a few spoon fulls of carb cleaner in the fuel and give it a really hot pre-heat,several times and seen if that works.i have had the small flame problem on a couple gas stoves,my back up 99 being one,and just keeping at it with the pre-heat has cleared the works out.
I would pull out the wick, unscrew the burner bell and jet and ensure that the burner stem is clear all the way through. A new tank seal is a must have. The current one will be hard and like plastic. It should be soft and rubbery. It may seal now but it will let you down soon.
1.5 mm. I would not bother about the graphite packing, unless you have evidence that it leaks - little flames around the valve shaft. Yonadav
On the question of ensuring the burner is clear all the way through: I have take apart the bell, burner and wick. After soaking everything in carb cleaner and opening the regulator all the way, I inverted the burner tube and filled it with carb cleaner. I could only get the fluid to drip through very slowly out of the upside-down jet nozzle. How "clear" is clear? Should I be able to get a steady stream of carb cleaner? A steady drip?
I think Dave Gibson's onto it. I had the same problem you've got with a couple of older 123's (not R's) that I rescued from the junk pile. You'd be surprised how much crud can get stuck in there that carb cleaner alone won't dislodge. As the hardened crud loosens up somewhat and bits dislodge it can actually worsen performance until all of it's totally cleared out. Heat, quench, scrape, rinse (with carb cleaner), repeat. Heat, quench, scrape, rinse, repeat. I was dumbfounded the first time I did that and got LOADS of old carbon dislodged, and all after I thought I had gotten everything out initially. The second time it happened wasn't a surprise - although given the small amount of maintenance that's needed for these little suckers I've never understood how some get so bad off. What are people DOING with these things?? If the jet's the problem then taking it out as suggested and seeing how much is clear will help pinpoint the problem.
By "take out the jet," do you mean the burner assembly, removing it from the tank? (Done.) Or is there a way to remove the nozzle piece at the end of the tube? The vertical tube appears to be all one piece but maybe not.
After you unscrew the burner bell, you have access to the jet - that is the little oval thing with the pin hole in the center. One of the holes in the key should fit over it, and allow you to unscrew the little jet from the top of the valve assembly. See the exploded diagram of the 123R on the Optimus site: 123R Yonadav
Yona -- Thanks for the tip. I should have realized this and did not. The burner tube (what's the right terminology?) and the jet (tiny piece at tip) are now separated and soaking in carb cleaner, waiting for me to get a chance to reassemble and test again. I'll post updates. Thanks to all.
The right terminology is vaporizer, when referring to the burner tube. Some folks like vibratory bath cleaners for bringing clogged jets back to life. Welcome to CCS. Al
http://www.base-camp.co.uk/exploded views/Optimus/123R Svea-Climber.htm At your earliest convenience, click on the link on one of Spiritburner's posts, re our sponsor. There is a link on that site for Optimus pressure stoves. When you see the parts list, don't panic. Just be aware of it. This link, (above) is for a 123R, still, it is interesting. The Base Camp site is a marvel of information. Best, Al
Don't forget, as well a lot of the real old stuff, we have the more modern exploded views here too: https://classiccampstoves.com/threads/84 Original 123 non-r in this catalogue: https://classiccampstoves.com/threads/214
