Optimus Trapper 81 Parts

Discussion in 'Stove Forum' started by Sebastian De Beer, May 26, 2023.

  1. Sebastian De Beer Australia

    Offline
    Joined:
    May 26, 2023
    Messages:
    19
    Location:
    Perth, WesternAustralia
    Hello everyone

    I am a newbie to this forum. I have several Trangia stoves but have just come across an Optimus Trapper 81 (misidentified as a Trangia) which is going (to my mind at least) fairly cheaply (AUD 35).

    It looks like the little knob on the flame adjustment lever is missing as well as one of the two o-rings on the safefill tube thingymajig.

    Could anyone help me out it specifying replacements for those two items please?

    Preferably metric but happy to convert from inches if that is the only info you have available.

    Thanks in anticipation.

    Sebastian
     
  2. Majicwrench

    Majicwrench Subscriber

    Offline
    Joined:
    Jun 21, 2012
    Messages:
    2,761
    Am sure you will just have to make something up for the lever knob. One of mine I was missing that knob, I don't recall what I put on there. Have to look. You do want something on that lever, it does get hot.

    The Oring you just need to take it down to an auto parts or hardware store and find an Oring that fits. Buy a couple, and put one in a bit of alcohol and see if it can take it. Keep those Oring lubed with something.

    They are great stoves, a bit odd, but special IMHO. Post pictures of it doin it's thing!
     
  3. Scrambler

    Scrambler Australia Subscriber

    Offline
    Joined:
    Jan 29, 2013
    Messages:
    1,146
    Location:
    Australia
    @Sebastian De Beer

    If the size isn't too small, pop in to an auto parts place (Repco, SuperCheap) and buy a whole tray of the o-rings for a few dollars. Probably easier than trying to get one, and possibly cheaper as well.

    The dimensions are the hole size "x" the thickness of the o-ring. The smallest in my ex-SuperCheap Viton kit is "2.5 x 1.8mm"

    If the tube dimeter is 2.5mm or greater, you should be able to use one from the kit.

    Despite the dimension mis-match, 7 of the 18 sizes in mine fit some part on an MSR pump well enough to function perfectly.
     
  4. Lennart F

    Lennart F Sweden Subscriber

    Offline
    Joined:
    Jun 24, 2017
    Messages:
    1,251
    Location:
    Vänersborg, Sweden
    There you had me to unpack my Trapper and check the rings, time to apply new silicone lubricant.
    Both O-rings are 1.78mm thick - outer diameters are 26mm upper ring and 24mm lower ring.
    I have the metric and non-metric standard 32 sizes red plastic box O-ring assortments and neither holds any ring thinner than about 2.5mm at that diameter so you need to get it from someone with a better assortment.

    Regulator knob is a standard plastic semi-soft found on lots of different wire feet etc. inner diameter 3.8mm.

    Optimus 81 Trapper manual.jpg
     
  5. Sebastian De Beer Australia

    Offline
    Joined:
    May 26, 2023
    Messages:
    19
    Location:
    Perth, WesternAustralia
    Thank you all very much for the information. I am picking it up tomorrow morning and will post some photos when I get back home.
     
  6. Harder D. Soerensen

    Harder D. Soerensen United States Subscriber

    Offline
    Joined:
    Oct 24, 2017
    Messages:
    2,156
    Location:
    Denmark
    @Sebastian De Beer
    For the missing knob on the flame regulator - that black plastic top from a valve on a bicycle tube will fit with a dab of good glue.

    They are great Cooksets and can run for a long time without having to refill + you can adjust the flame from outside the windscreen.
     
  7. Sebastian De Beer Australia

    Offline
    Joined:
    May 26, 2023
    Messages:
    19
    Location:
    Perth, WesternAustralia
    Just arrived home after picking up my “Trangia”. It’s missing the adjustment knob and the lower oring on the safefill tube but I have already identified replacements for these items D01262A1-4F64-435C-9453-B04416789C8E.jpeg FC82D315-293D-4F9B-A396-219548B89FA3.jpeg F6E8EEA3-1715-4E47-AEE7-F6153D29514B.jpeg 0CEB0417-19EC-4752-841F-5F5F89502858.jpeg with the help of the kind gentlemen above. Will post photos of it running as soon as possible.
     
  8. Majicwrench

    Majicwrench Subscriber

    Offline
    Joined:
    Jun 21, 2012
    Messages:
    2,761
    A couple of brief warning.....the SafTfill things often leak, so fill stove somewhere other that where you are gonna cook. Is easy to end up with a puddle under stove.

    And, later 81's had a little knurled plug on the side, this was to make sure you don't over fill. Do a search on here for your stove and you will learn a lot.

    One of mine simmered much better than the other, and that's the point of this thing right?
    The one that didn't simmer I had to modify the air valve to close off better.

    Looking forward to more pictures! Enjoy your Trangia