Sievert SVEA 123 1966 - Flame Surging

Discussion in 'Fettling Forum' started by SimonFoxxx, Apr 14, 2019 at 4:33 AM.

  1. SimonFoxxx

    SimonFoxxx Subscriber

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    It appears that my 123 has (without good reason) decided to embark on a surge and back cycle. Is this a consequnce of a wick problem, or something else.

    I have checked for leaks etc. A comparison with my 1950's Optimus 80 reveals lower flame power too. The Optimus 80 takes 8 minutes to boil 1 litre water, whereas the 123 takes 10 minutes. It should take about the same time. Any advice much appreciated.
    Cheers
    Simon Foxxx
     
  2. CW

    CW United States Subscriber

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    Fuel is it correct is it old? If it's not leaking check snd see if the fuel jet needs cleaning. How old is the pip sometimes these leak with heat and pressure applied. Worst a case take it apart, clean it and change the wick. But sounds like fuel or a dirty jet.
     
  3. Tony Press

    Tony Press Australia Subscriber

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    @SimonFoxxx

    1. Give it the dunk test: cold stove in hot water to check for leaks (fuel cock closed).

    2. If no trouble there, take the nipple off and blast the vapouriser and nipple with carburettor cleaner.

    3. If still in trouble, check the wick.

    Of course, always check fuel as the first test.

    Cheers

    Tony
     
  4. SimonFoxxx

    SimonFoxxx Subscriber

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    Fuel in good, and dunk test in water just boiled is negative.

    I will try removing the jet and cleaning the vapouriser. Last resort
    I will detach the vapouriser and check the wick.

    Thanks for the suggestions, team.
    Cheers
    Simon Foxxx
     
  5. snwcmpr

    snwcmpr Subscriber

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    Before removing the vaporizer add a drop or two of penetrating oil. Kano Kroil, or 50/50 acetone/auto trans fluid. Let it set. I have done this for up to a week, or more, so the vaporizer comes off easier, and less chance of deforming the thin tank material.

    Ken in NC
     
  6. threedots New Zealand

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    Hello @SimonFoxxx .
    I would say that the wick is becoming blocked with debris or carbon from someone running the stove until dry. Cheers, John
     
  7. snwcmpr

    snwcmpr Subscriber

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    Has any one tried lacquer thinner to clean a wick without removal?
     
  8. Doc Mark

    Doc Mark Subscriber

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    Hey, @snwcmpr ,

    Since the major part of wick failure and filth, is up in side the burner vaporizer, I'm not sure that adding Acetone to the font, without removing the wick, will be efficacious. Just my 'tuppence....

    Doc
     
  9. snwcmpr

    snwcmpr Subscriber

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    Lacquer thinner! It is known to break down old dried gasoline.

    I picture:
    Cold stove with lacquer thinner in tank.
    Upside down.
    Valve closed, tank sealed, jet removed.
    Warm tank somehow.

    Open valve and watch lacquer thinner flow out.

    Just a thought. If it works, it is easier than removal of a 50 year old vaporizer.
    If not, no loss.

    Ken in NC
     
  10. Radler Switzerland

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    Somebody compares boiling time for 1 litre of water with a SVEA 123 and a Optimus 80. Boiling time is 8 and 10 minutes. Now he is asking the whole world abut a "problem"!
    The "problems" in this forum are becoming more and more ridiculous!

    Not with me!
    Radler
     
  11. Tony Press

    Tony Press Australia Subscriber

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    @Radler

    I understood the problem to be the “surge and back cycle”, not the time taken to boil.

    I’ve had a Svea 123R do the same: large flame-small flame-large flame-small flame...

    I fixed it eventually. The home-made wick was far too tight in the vapouriser.

    Tony
     
  12. SimonFoxxx

    SimonFoxxx Subscriber

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    Ok, thanks for the hint. Taking out the vapouriser is a last resort to fix. I will try running a few more tank fuls of fuel. To try to clear any blockage.
    Cheers
    Simon Foxxx
     
  13. SimonFoxxx

    SimonFoxxx Subscriber

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    Hiya Radler,

    Thanks for your point of view. The problem is not a comparison of boiling times, I made the comparison as part of problem diagnosis, surging being the issue. People here have been very helpful. A first world "problem" if you want to call it that.
    Cheers
    Simon Foxxx
     
  14. Radler Switzerland

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    @SimonFoxxx
    If not the difference between 8 and 10 minutes is your problem, I have misunderstood you. Sorry for that!

    Two reasons for surging can be: water or unsuitable fuel in the wick from a previous user. Another reason can be too much fuel in the tank, ¼ of the volume must be air. This is very essential.

    Regards
    Radler
     
  15. Mark Layman

    Mark Layman Subscriber

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    Exactly @Tony Press
    Fuel starvation. Wick too tight maybe but most likely original wick so either carbon or burnt or little of both.
     
  16. SimonFoxxx

    SimonFoxxx Subscriber

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    All good, I will continue to work on this. I may need to undo the vapouriser for a wick inspection and possible replacement.
    Thanks to all for feedback.
    Cheers
    Simon Foxxx