Optimus 111 Underperforming

Discussion in 'Fettling Forum' started by paultee, Dec 31, 2021.

  1. paultee Canada

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    I have a 111 and a 111B. Both needed standard fuel cap seal/pip and NRV replacement pips and pump cup help but the 111 has never reached the power output of the B visually, sonically, nor in boil times (which I don’t care about but do illustrate that I wasn’t imagining underperformance). The 111 tested with Coleman fuel instead of kerosene remains a bit weaker. 20-30% less output than the seemingly flawless 111B I can test it against.

    While I’m happy with a 6min/1L boil on the 111 using kerosene, I know it can do better.

    What could I be missing in the full rehab of the stove?

    So far I’ve confirmed proper new seals on the cap, NRV is strong and working under 30-plus pumps. Old jet was enlarged, so I put in a new one, tried a brand new spindle/needle with no change, new graphite packing made no improvement, but is sealed well.

    I did a few 30min swims in diluted vinegar. I did a handful of heat and quench of the burner.

    I’m not getting any loose carbon.

    The burner passed multiple dunk tests.

    Is it conceivable that the 111 I have is just a 6min/L boiler with a weaker performance profile compared to my 111B?

    What else could I try? Could I have crack that doesn’t make itself obvious during a pressured dunk?

    should I go harder, hotter, longer on the heat and quench?

    I also ensured the brass mesh was clean and clear, so I’m out of ideas!
     
    Last edited: Dec 31, 2021
  2. hikerduane

    hikerduane Subscriber

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    Swap jets from one stove to the other? The 111 has a kero jet? Have not run my 111's for a few years, but have my "B".
    In the past, I understand a few have ruined burners from rare stoves heating and quenching. I've had no luck using 10lbs. pressure blowing compressed air thru a burner while using a torch on the burner to burn out carbon. Maybe my torch wasn't up to the task.
    Duane
     
  3. paultee Canada

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    @hikerduane

    The original jet on the 111 was larger than a brand new Svea 123 jet, but an even smaller 111 jet won’t be in the cards for me unless I get lucky and find new levels patience, I suppose.

    could there be that large a performance drop from a brand new Svea 123 jet to 111 kero?

    I will probably leave this 111 stove as an underperformer, and I do LOVE the 111B and have cheap Coleman fuel access in Canada, so it’s just that NRV peace of mind factor I’m not bothered by because I’m careful about maintenance.

    I guess I’ve just hit a wall on what else I could try (or retry).
     
  4. hikerduane

    hikerduane Subscriber

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    Remember kero jets need to be smaller than gas jets. I find gas stoves are faster/hotter than kero.
    Duane
    PS: I love my stove time when bping or camping, I don't own the new Jetboils or MSR Windburner, they are too quick.
     
  5. BradB

    BradB United States Subscriber

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    I don’t ever run my 111 on kerosene at more than 10 or 12 pumps. Pumping more doesn’t seem to do anything. My 111 burns hotter with shorter boil times than my 111B, which I no longer have.
     
  6. paultee Canada

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    @BradB

    Something is definitely amiss with the 111 kero, but I just can’t find it. It clearly lacks power but not being obstructed in an obvious way. And agreed on the 10 pumps—which is plenty for my 111b, but I just mentioned the higher pumping as part of the head-scratching about how the 111 is just not performing at top power.
     
  7. Scrambler

    Scrambler Australia Subscriber

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    I'm no expert to tell you how to make this better. My own 1960s 111 does 5:20 per L, my X-GK (and it has a worn jet) does just under 4 min.

    What time did you run with the worn jet in the 111?
     
  8. paultee Canada

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    @Scrambler the times with the old jet were also slower but flow was rich—all tinged with yellow. I have no way of knowing if it was ever even the right jet as the 111 came in pieces. That said, I have no reason to believe it wasn’t the original jet, as it all looked to have been paired for a long time till I started rehabbing it.

    and my 111B does 1L in under 5, and just blasts with a force unmatched by the 111 I have.
     
  9. Tony Press

    Tony Press Netherlands Subscriber

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    @paultee

    I use my roarer 111s, and my 111T regularly — all on kerosene. All three are powerhouses. Increased pumping makes the roarer burners sound like jet engines.

    Do you have a way of checking the size of the jet in the nipple of your 111?

    Are you using it with the pricker needle? If so, measure the diameter of the pricker wire and compare it to your 111B.

    Cheers

    Tony
     
  10. paultee Canada

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    @Tony Press

    My “measuring” was using an old manual pricker and seeing that it was loose in the old jet (side to side) and not in the new one. That and the blue flame in the 111 vs yellow tipped was enough to me to jump to that conclusion.

    From what I’ve read on here, the 111 is more tolerant of jet diameter, so I figured the weaker output is caused somewhere else in the chain. Also it seems to be quite hard to source a proper 111 kero jet, so I’m just stumped.

    as it stands I might try one more round of heat/quench with more tapping, but beyond that, I just don’t know what else could be the fault other than a crack I can’t find. It’s been a frustrating journey!
     
  11. CW

    CW United States Subscriber

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    pump it up and do a dunk test it might be losing pressure (nrv, cap gasket or pressure relief pip in cap).
     
  12. JP2

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    Yoa, maybe you have a leak, try it with the SRV from 111b or do a dunk test.
     
  13. Twoberth

    Twoberth United Kingdom SotM Winner Subscriber

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    Did you try this? What was the result?
     
  14. Daryl

    Daryl United States SotM Winner Subscriber

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    Always good to have stove work 100%. Seems like you have gotten good advice, won't be long. Maybe not the end of the world though. I use stoves in pairs so if you use the hot one to boil water and the cool one to cook food you may find this works. Have a pair of 502's one is for boiling and the other is the cooker. BTW Trying to get to weak spring? in pick up tube. Have tried several methods to get burner cup off but don't want bend it all up. Can still burn pancakes and eggs so it good.