Friday Fettle: Optimus No.00 and defect NRV

Discussion in 'Fettling Forum' started by Trusty McTrad, May 7, 2021.

  1. Trusty McTrad

    Trusty McTrad United Kingdom Subscriber

    Offline
    Joined:
    Mar 9, 2021
    Messages:
    69
    Location:
    Norway
    Dear friends,

    Last night I bought an old Optimus 00 which had not seen much use in decades. Having inspected and oiled the pump leather I quickly realised to my disappointment that the NRV was not working, as no air made its way into the tank, even when pumping hard. I have restored a couple of newly acquired kero stoves lately, a 1930s Radius 21 and a Høvik Verk 2Pt Primus with great results, so I thought the Op.00 would be a suitable addition to my collection. That said, I have never had to replace the NRV, and had to improvise the NRV wrench/tool.

    I was a little apprehensive about undertaking the removal and dismantling of the NRV, but thanks to the various members of CCS who have written eminent posts about NRV removal and repair, I felt moderately confident that I was up to the challenge. I took a standard hex driver and filed an opening to fit the NRV (see picture), feeling my way to the right size until the fit was snug. The NRV came out ok, and with some solvent oil spray I was able to take it apart after five minutes of soaking. The rubber pip seemed ok once it came unstuck, so I merely elongated the spring a little and put the NRV back together, guided by my memory of CCS posts I had read in the past.

    With the pump and NRV restored, I proceded to do a test burn, which was less than successful. Fuel was leaking from both underneath and above the spirit cup, and no in-situ tightening of the burner head would fix the leak. Having taken the burner head apart, cleaned both gaskets and screwed the burner head firmly back together using two wrenches, I screwd the burner back onto the tank using only hand force, and voila - successful leak-free burn at maximum pressure, and with a flawless flame pattern indicating a nozzle in good working condition.

    I then cleaned and polished the tank, and I must say I am quite happy with the result. I also found a 1 litre British Army utility pouch that just about holds the entire kit including an 80ml spirit bottle and tools, so I am pretty sure this will be the stove I am taking camping this weekend.

    I will add the pictures below. What do you think?

    Wishing everyone a pleasant weekend!
    T
     
  2. Trusty McTrad

    Trusty McTrad United Kingdom Subscriber

    Offline
    Joined:
    Mar 9, 2021
    Messages:
    69
    Location:
    Norway
    92687148-DF65-4747-AFAD-5B3E49D035D5.jpeg 7AA953E2-64AC-4D21-A094-04C7AFAACEB0.jpeg 5EF38D86-04F7-4B22-A727-E168EB205BB6.jpeg 3A9F2C17-350B-4B27-92B3-B066DB3B781B.jpeg Pictures of today’s project:
     
  3. hikerduane

    hikerduane Subscriber

    Offline
    Joined:
    Mar 1, 2010
    Messages:
    7,408
    Great you got it running. I usually try poking the NRV with some wire first if stuck, may need to eventually replace the pip. The burner on these uses just a small lead washer to seal the burner to the fount. I only replace the gaskets if they leak. Seems the gaskets seal best if only hand tightened, I've tried a few different ways, wrenching usually makes a leak worse, that's why I hate to replace gaskets.
    Duane
     
  4. kerophile

    kerophile United Kingdom SotM Winner Subscriber

    Online
    Joined:
    Sep 23, 2004
    Messages:
    13,036
    Location:
    Far North of Scotland
  5. A A C

    A A C Norway Subscriber

    Offline
    Joined:
    Dec 2, 2020
    Messages:
    158
    Location:
    Agder Norway
    @Trusty McTrad . Great tip about the utility pouch . Ill be on the look out for one :)
     
  6. CW

    CW United States Subscriber

    Offline
    Joined:
    Dec 19, 2016
    Messages:
    487
    those are great stoves and congratulations on the repair. I would pick up a rebuild kit from the Fettle Box, it will have all the seals and parts to make it last another 50 years.
     
  7. ROBBO55

    ROBBO55 Subscriber

    Offline
    Joined:
    Oct 27, 2014
    Messages:
    1,535
    Location:
    Somersby, New South Wales, Australia
    Congratulations, the 00 is a very versatile stove and well worth the effort to get working. :thumbup:
     
  8. Trusty McTrad

    Trusty McTrad United Kingdom Subscriber

    Offline
    Joined:
    Mar 9, 2021
    Messages:
    69
    Location:
    Norway
  9. Trusty McTrad

    Trusty McTrad United Kingdom Subscriber

    Offline
    Joined:
    Mar 9, 2021
    Messages:
    69
    Location:
    Norway
    Thanks for your comments guys. I can report that the stove performed well during this weekend’s overnight in the woods. Nice weather, but I was sleeping at 320m altitude, so in the wee hours it was a chilly minus 5 Celsius, and while it made sleeping a bit difficult, it made it all the more tempting to fire up the stove and cook an early breakfast.
     
  10. A A C

    A A C Norway Subscriber

    Offline
    Joined:
    Dec 2, 2020
    Messages:
    158
    Location:
    Agder Norway
    Great photo. Good to see the Optimus in its natural habitat !