Optimus 22 right roarer underburns

Discussion in 'Fettling Forum' started by Skopar, Aug 10, 2020.

  1. Skopar

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    Hi. This is my first thread here. Until now I have only commented threads open by other, but now I am lost about the way to go to restore this stove.

    So yes. It looks like 111 roarers can also underburn. Go figure! I bought an Optimus 22 from the early 60s. The right roarer burner is the one with more wear and it underburnt with a huge orange flame. I assumed that the jet had to be changed. I have not changed the needle as it is almost new. I have not trouched actually. I have changed nothing else in this burner.

    With the new jet, the right bruner has improved. Now the flame is smaller. However, it still underburns when it is at maximum power or the cleaning needle is almost out. It does not underburn most of the times when simmering or at medium to maximum power, I mean with a flame that is just smaller than maximum. It does not underburn when the flame has the size of the left burner. Also, despite having the new jet, the flame at maximum power is still bigger than that of the right burner. The right burner has a jet that is not old either and it always has a blue flame, much like that of my Optimus 111 roarer.

    I noticed that the underburning has nothing to do with wind. It has nothing to do with high or low pressure. It does not underburn at low pressure when the fuel is extinguising! It has to only do with being at maximum power. Otherwise, the burner provides a very blue flame, except when it start underburning. Then, when underburning, suddenly the whole flame becomes orange.

    Any advice please?
     
  2. presscall

    presscall United Kingdom SotM Winner SotY Winner Subscriber

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    @Skopar Ensure the jet nipple isn’t leaking vapourised fuel at the threads. It may be a damaged jet seat on the burner - a small scratch. Make sure the jet’s screwed in tight, short of stripping the threads of course!

    John
     
  3. Skopar

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    Thank you! That make sa lot of sense since it mostly underburns from one side of the jet. I already screwed tight, but with no sucess. Cleaning the threads is next. I hope I need not to buy a new burner... I wanted to keep it as original as possible. Will report back.
     
  4. presscall

    presscall United Kingdom SotM Winner SotY Winner Subscriber

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    @Skopar I’ve had this happen on Optimus 111. There was no damage to the jet mount mating surface on the burner, but the jet came unscrewed enough to spring a leak. A tiny bit of graphite grease on the jet threads before fitting will help tighten the jet to the full without the threads binding.