British Army No. 2 jet size

Discussion in 'Fettling Forum' started by Sternenlicht, Mar 17, 2020.

  1. Sternenlicht

    Sternenlicht Subscriber

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    Hej all, currently I'm fettling a british army no 2 from 1972. Unfortunately I broke the original jet with its ( I guess) much to large hole. I brazed another jet into it, hole diameter about 0.29mm. But the flames resulting are to powerless. I think the jet size is to small, what is the original size?

    Ciao, Bastian

    IMG_20200317_204101.jpg
     
  2. presscall

    presscall United Kingdom SotM Winner SotY Winner Subscriber

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    @Sternenlicht
    I don’t have one to hand but I’d expect 0.32mm. It doesn’t seem much more in diameter but it’s about a third more in area.

    John
     
  3. Sternenlicht

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    @presscall
    I only had kerosene jets to braze in, so had to start with that small diameter. I will drill the jet. The original jet was opened to 0.40mm, which seems to be too large. Thank you!

    Ciao, Bastian
     
  4. presscall

    presscall United Kingdom SotM Winner SotY Winner Subscriber

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    @Sternenlicht
    I had a similar experience with a Russian Prim Compact stove. The stock jet (0.34-0.35mm) passed too much fuel, so I reduced a spare jet to 0.23mm. That was too small and 0.32mm was right.

    My mint British No.2 (modified) came with too large a jet. An Optimus 111 (kerosene) 0.32mm jet made it right.

    John
     
  5. Sternenlicht

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    @presscall
    Unfortunately the thread of the jet of the no. 2 mod differs from the no. 2. I also tried to take its jet,and also some spare jets from my optimus stoves (199, 155, 535, all the same jets)
    I just ordered some 0.32mm drills, hope they are coming soon.

    Ciao, Bastian
     
  6. presscall

    presscall United Kingdom SotM Winner SotY Winner Subscriber

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    That’s right, yes. Those examples of two stoves with ‘stock’ jets too large was just to show it happens.
     
  7. Simes

    Simes Subscriber

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    As a 'petrol' stove the No 2 I suspect is very forgiving on jet sizing. I've no idea what condition the jet in mine is but as I've not gone near it since I bought it and it's quite happily blue so I'm not touching it.
     
  8. CRAZY CRAB

    CRAZY CRAB United Kingdom Subscriber

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    got my jet , now I got 2 sizes of prickers, the small one goes into a 96, and the bigger one wont, the bigger one goes into all me other 2pt ones, and me No2 jet, it is around .038c or .012in, best I can do