Optimus 11 pump cup size

Discussion in 'Fettling Forum' started by brian kinne, Jun 22, 2019.

  1. brian kinne

    brian kinne United States Subscriber

    Offline
    Joined:
    Aug 15, 2018
    Messages:
    20
    Location:
    camden, ny 13316
    My new to me Optimus 11 runs but poorly. I have freshened the cap gasket and PIP. The pump works but requires way too much force. Removed the pump as a unit. The leather cup that was fitted is way to big for the stove. No way I can ever git the cup back in the stove. The cup must have been bone dry when it was 1st fitted than oiled which swelled the leather. The 11 has the pump next to the fuel fill port. The rod is shorter but similar in design to the latter 111 stoves that have the pump in the end of the fuel tank. I have tried the 111 cup and several others that I have on hand. They were all 2 large and in my opinion 2 thick. Anyone know for sure what I need. Or maybe there's a secret to fitting pump cups that I never learned. Thanks.
     
  2. JP2

    JP2 Subscriber

    Offline
    Joined:
    Jun 26, 2018
    Messages:
    420
    Location:
    Canada
    Hi
    What do you mean by, The pump works but requires way too much force. Is it on the way down (NRV problem) or on the way up (pump problem)?
    Any pictures. ??????
     
  3. brian kinne

    brian kinne United States Subscriber

    Offline
    Joined:
    Aug 15, 2018
    Messages:
    20
    Location:
    camden, ny 13316
    Thanks for the reply JP2. Too much force each way. The sides of the cylinder are smooth. I believe it is just 2 much leather
     
  4. JP2

    JP2 Subscriber

    Offline
    Joined:
    Jun 26, 2018
    Messages:
    420
    Location:
    Canada
    Have you oil it? What is happening when you try a too long rod on the way down, is it still difficult?
     
  5. brian kinne

    brian kinne United States Subscriber

    Offline
    Joined:
    Aug 15, 2018
    Messages:
    20
    Location:
    camden, ny 13316
    Have not tried another rod. The existing rod appears to be in good shape and properly assembled. I am going to try trimming a new leather cup down a bit and see how it works.
     
  6. JP2

    JP2 Subscriber

    Offline
    Joined:
    Jun 26, 2018
    Messages:
    420
    Location:
    Canada
    First if I was you, I will try another rod ,even too long, to see if the NRV in ok.
    On a 111, the tube is 14 mm.
    I have never anybody that wanted to trim a cup before.
    Here is a link that shows how the pump work to fix the first problem.
    Have fun

    Typical pump assembly
     
  7. JP2

    JP2 Subscriber

    Offline
    Joined:
    Jun 26, 2018
    Messages:
    420
    Location:
    Canada
    Have you tried anything like that to enter the cup. Beer or pop can or milk container. Etc IMG_20190622_131911.jpg
     
  8. ECHO1

    Offline
    Joined:
    Jun 29, 2013
    Messages:
    75
    Brian,
    PeterD from E---Y
    What do You need done.
     
  9. ECHO1

    Offline
    Joined:
    Jun 29, 2013
    Messages:
    75
    Brian,
    I think I have an Optimus 11 Pump Leather. let me dig and see what is in the Bit bag and I will let you know
    PD
     
  10. brian kinne

    brian kinne United States Subscriber

    Offline
    Joined:
    Aug 15, 2018
    Messages:
    20
    Location:
    camden, ny 13316
    Thanks Peter. A new cup will get me going or tell me I have a NRV problem. Brian.
     
  11. Tantra

    Offline
    Joined:
    Mar 4, 2018
    Messages:
    109
    My Optimus 11 stove also have same troubles
    I check the NRV is work
    I don’t have original tank lids
    Now I only find two possible reasons
    Pump leather and lids
    Do you know how to get that parts ?
    Thank you
     
  12. brian kinne

    brian kinne United States Subscriber

    Offline
    Joined:
    Aug 15, 2018
    Messages:
    20
    Location:
    camden, ny 13316
    Sorry Tantra. Learning as I work on the 11.