Radius 42 - too large jet?

Discussion in 'Fettling Forum' started by Lennart F, Aug 24, 2019.

  1. Lennart F

    Lennart F Sweden Subscriber

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    My newly aquired Radius 42 had a test firing last night and today I had to pick the jet repeatedly.
    OK - open the burner, take out jet and wick, wash off a slight soot residue from wick and scratch and blow a small amount of soot from the burner - reassembly and firing up, strong and steady flame but yellow tips.
    A few minutes later it suddendly went roaring, guess it was the last coke leaving the jet.
    The pricker feels like I got same size jet as in my Primus/Radius size1/5 stoves and it looks identical, the parts list indicates it should be another jet(smaller?) - yes, I made the burner plate in 5 minutes to make it running an that key just was in my pocket... IMG_20190824_195425.jpg
    IMG_20190824_195438.jpg IMG_20190824_195453.jpg IMG_20190824_195527.jpg
    The stream from the jet looks quite wide and conical compared to my other stoves.
     
  2. Lennart F

    Lennart F Sweden Subscriber

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    It passed the tea test in a hurry leaving a black bottom on the Trangia kettle.
     
  3. kerophile

    kerophile United Kingdom SotM Winner Subscriber

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    Hi, this is the jet pricker intended for Radius No.42 stove.

    Pricker Radius

    Tony @Tony Press measured the pricker wire at 0.21 mm diameter.
    The jet aperture of a No.1 or No.5 type stove has a diameter of 0.32mm.

    Best Regards,
    Kerophile.
     
  4. Lennart F

    Lennart F Sweden Subscriber

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    As I suspected - then I need a smaller jet.
     
  5. Lennart F

    Lennart F Sweden Subscriber

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    Late update but I made some more tests last year.
    At first testing jet from a nicely burning Optimus 8 - better but not good - jet and bell from the 8 burning fine but a little too hot.
    Later I came across a description of a (back then)cheaper fuel widely used in Sweden from 1920's into 1950's called "lättbentyl" consisting of 75% gasoline and 25% ethanol - I had already suspected that my 42 could be tuned for that fuel.
    As I had 95E10 and E85 at home - it would be similar mix rate to make roughly that old fuel so I mixed a bottle and fueled up.
    Suddendly it worked like a charm, burning perfectly.
    Sorry - didn't take a picture.:roll:
     
  6. presscall

    presscall Moldova, Republic of PotY Winner SotM Winner SotY Winner Subscriber

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    @Lennart F
    Thanks for the update. Interesting that a stove was ‘tuned’ for a specific fuel as though it were an old motorbike!

    You haven’t said what the fuel producing the yellow flames was, but I’m assuming Aspen, Coleman fuel or maybe regular unleaded pump gasoline?

    John
     
  7. Lennart F

    Lennart F Sweden Subscriber

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    Aspen 4 as it should be in a Radius 42.