Primus omnifuel Troubles

Discussion in 'Stove Forum' started by Crang, Jan 11, 2020.

  1. Crang United States

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    Hi All-

    Just got a Primus Omnifuel and am taking it for its maiden run. Ignore my post title- I cant edit it but its an Omnifuel! First tried an MSR butane type canister and all was good. Switched the jet to the correct one for white gas, filled the tank with Crown white gas and the trouble started. I can prime it but cant get it to go to a blue flame.

    Ive cleaned the jet repeatedly, used compressed air in the line and intake on the pump, checked the leather plunger on the pump, checked the small brass and oring bit that seals the pump, removed the fuel filter finally on the intake and it doesnt make a difference. The output pressure seems sporadic no matter what I do (even though there is pressure in the tank). By some miracle I got it working a single time and then back to the same problem. If I do get past the priming to the blue flame- it only lasts a few seconds before it sputters and goes back to a big fireball of yellow flame.

    What is left to check? About ready to give up and see if I can get a replacement.
     
  2. kerophile

    kerophile United Kingdom SotM Winner Subscriber

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  3. Crang United States

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    Yes- had followed everything on that thread. Still no joy. The system is definitely cleared of debris and the fuel filter has been removed until I get it working to make sure that wasnt an issue.

    Starting to wonder if the .37mm jet is defective or if something internal is drilled incorrectly. Followed the trouble shooting video on the Primus site and did every step and it still doesnt check out. Hmmm.
     
  4. Crang United States

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    Got it! Some factory grease on the valve stem kept washing into the system everytime the fuel flowed through it. So I was cleaning it just to have it partially clog the jet again. Cleaned that plus everything else again and works like a charm. Frustrating but I know the stove front and back now at least-

    Thanks and thanks for having me on this forum.
     
  5. presscall

    presscall United Kingdom SotM Winner SotY Winner Subscriber

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    @Crang
    Good outcome. Thanks for posting - it may help someone with the same problem.
     
  6. JP2

    JP2 Subscriber

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    Welcome to CCS
     
  7. Crang United States

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    Thanks! I've been a lurker for some time so happy to finally join.
     
  8. snwcmpr

    snwcmpr Subscriber

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    Welcome to CCS.
     
  9. HunterStovie

    HunterStovie United States Subscriber

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    @Crang

    Welcome as well.

    What version of the Omni-Fuel do you have? Pictures help.
     
  10. Crang United States

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    Its the current plane jane Omnifuel (3289 I believe). I have already put it back together but the issue was with the spindle with o-ring. Lots of grease ended up in front of the oring on the spindle. Guess butane could go by it but the white gas flowed it right into the jet. The entire length of this piece had a white grease film on it:

    7330033731903_SS18_a_spindle_w_oring_for_3289_5pc_primus_22.jpg
     
  11. HunterStovie

    HunterStovie United States Subscriber

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    I've had that same problem once before. If it was the Omni-Fuel II that you have then there is a concern with the burner bell and flame plate.

    I love my Omni-Fuels.
     
  12. Chris Colleman Belgium

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    Well same here, bought an Omnifuel Ti with the silencer and it was a pain with white gas. Jet clogged up every chance it got. Double, tripple checked I was using the correct jet size. But no avail. Switched to Primus Power gas and it’s a different stove all together. No problems at all.

    I’d like to get to the bottom of this, but at the moment a hot beverage is paramount. The omnifuel has been put on the backburner :-)
     
  13. hikerduane

    hikerduane Subscriber

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    I hate this. The MSR Dragonfly is so much more adjustable. The Omnifuel orings stick.
    Duane
     
  14. Afterburner

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    I have used my Omnifuel around ten years without major problems. Once fuel filter was blocked, but no other challenges.

    Have you tried how it works with original flame spreader in roarer configuration? Just for fun test how other jets work with white gas. Maybe jet has some defect? Jet size is not so critical. I have used kerosene jet also for white gas and propane/butane and it works fine.
     
  15. afoton

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    If I got it right, Omnifuel has no internal cleaning needle.
    When using a needle from the outside, one just push the debris into the burner, and it will clogg up the jet as soon it get the chance of it. To get rid of the debris, one has to remove the jet and get it out of the burner.
     
  16. Crang United States

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    ^^ This. Plus a total breakdown and cleaning- jet, lines, spindle valve, etc.Otherwise grease from contaminated parts just moves back to the parts I cleaned. Cleaning one part at a time and testing again was not effective.
     
  17. Chris Colleman Belgium

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    The stove was a bit troublesome from day 1. Each time it cooled down, next start-up was problematic. Tried several of the jets it came with and the nicest burn was with the specified jet for white gas.

    Indeed for a decent cleaning you need to get the jet out and push through from the inside. When everything is just a bit too hot for the touch,... well that is kind off troublesome.

    Adding the silencer caused more problems than it cured.

    I’ve come to the conclusion that either it’s me not running the stove long enough for it to burn clean and hot. Or there is some inherent problem I’m not aware off.

    Failing gaskets and hose the first time in the second fishing season. Well that was it. Ordered parts, gave it a good lookover and used the gas option. Was a completely different stove.

    I’m giving 3 stoves a tryout at the moment. Primus Mimer with a small gas canister, Optimus Svea and a probably 25 year old “new old stock” Coleman sportster 533.

    Maybe I’ll revisit the omnifuel in the future just out of curiosity.
     
  18. snwcmpr

    snwcmpr Subscriber

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    The first one sounds easily solvable.
     
  19. Chris Colleman Belgium

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    Probably is the easiest solve indeed. But I just kind of reasoned that when I’ve got blue steady flames. Well it’s running OK.
    No temperature gauges on these things.

    I’m a small engines and tractor mechanic. Use to 2-stroke/4-strokegasoline or 4-stroke diesel internal combustion. This pressurised gas/ liquid white gas combustion has me a little out of my comfort zone.
     
  20. Chris Colleman Belgium

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    As I had some time on my hands. And when something niggles me,.... gave the omnifuel TI a lookover and another burn test.
    Much to my amazement and amusement, jet sizes aren't all that acurate. But be that as it may,... a hole is a hole.

    So investigated further and found some poor workmanship. Where they brazed the tube into the jet housing. Well a few extra holes are all it takes to make life a little complicated.
    And prohibit me from my well earned cup of tea during a fishing trip.

    I'll give Primus a shout and if that doesn't help braze it myself.

    What do you guys think??
     

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