Optimus-Princess P-39A

Discussion in 'Other brands' started by sailingcal21, Jan 15, 2012.

  1. sailingcal21

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    Looks like the P-35 except the knob linkage is straight through the front of the stove. This came off of a 1981 O'Day 34 sailboat.

    Here's the front and top of the stove.

    1326668337-Optimus-Princess_P-39A_1.JPG

    Here's the burner. Is this a #209 burner? I'd like to replace both or get a rebuild kit.

    1326668233-Optimus-Princess_P-39A_Burner_1.JPG

    Can't seem to figure out how to adjust the air/fuel mixture.
    1326668702-Optimus-Princess_P-39A_Burner_2.JPG
     
    Last edited by a moderator: Jun 26, 2015
  2. hikerduane

    hikerduane Subscriber

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    It looks like my Optimus 45A burner. I stumbled something that worked for me. Be sure the three parts to the cap are clean and the middle "T" cap can move up and down freely. Mine was rusted up and I got it to run great a few months ago after cleaning the rust off some more, but a month ago when I tried to fire it up, it had under burn. From what I gather, the middle cap, the "T" cap slides up and down with pressure. My parts have some deep rust, so I wish I could come up with some new caps. Good luck.
    Duane
     
  3. Doc Mark

    Doc Mark SotM Winner Subscriber

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    Greetings sailingcal21,

    Welcome to CCS! Your burners are actually very nice, and supposedly quite efficient, as Meths burners go. An Optimus 45A, using those same burners, was rated ahead of many white gas stoves in some important reviews and testing back in the 1970's. Check with Shirlene, at A&H in CA, as she sent me some burners like that a year or so ago. It's quite possible that she has all the replacement parts you might need. But, before you replace the burners, you might just do a deep cleaning, as HikerDuane suggested. That is very probably all that they will need. Later versions of that same burner had adjustable air/fuel mixing attributes, with several models using different but similar ways to get that done. Once tuned up, you'll be glad you kept those burners

    As HD so rightly suggested, get all the rust, grime, or dirt removed from all burner parts, replace all the seals, and then see how it works for you. You might be surprised at how good those burners will work, if they are not damaged! Good luck, and keep the questions coming, so we can help as we can. Take care, and God Bless!

    Every Good Wish,
    Doc
     
  4. sailingcal21

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    Thanks for the info and support. This disassembled burner was leaking a bit with the valve closed when the tank was pressurized so I figured that taking it apart wouldn't hurt.

    I plan to clean it up as best as I can and then fire her up again.

    So far when burning, I get a blue flame when the knob is just cracked open, but when I open it more it turns from blue to a greenish/yellow and is more of a flame. I'll post some flame pics when I put it back together.

    Once again, thanks for the input.

    Scott
     
  5. dspearsy2k

    dspearsy2k United States Subscriber

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    First off, Welcome to CCS. I had one of those. As the factory in Sants-fe Springs was only 50 miles from Newport Beach, I bought local.
    To my way of thinking, those are the best alky burners made. Air adjustment is automatic, if the center hat can move freely. If it jambs (it usually will stick in the down position) they will be rich at higher settings (yellow flame).
    Use a wire wheel in a drill to remove all rust, spray with WD-40, and test by sliding inner cap on mixing tube. The green flame is caused by desolved copper from the inside the burner or tank. That will clear within a tankfull. Valve closed leak... OK, That is usually caused by a misadusted cleaning needle. If you'll notice the cleaning needle is a bit longer than the standard kerosene type. So.. 5 clicks on reassembly just dosn't do. 4 Max. Otherwise the needle bottoms in the burner a dosn't allow shutoff. As for changing burners, all depends on fuel choice. If you choose alcohol, don't change the burners. Just rebuild or fix them. If you choose kerosene, burners will cost!!! And they are getting very hard to come by. Optimus-Primus 207b's or equivlent. You can buy alot of alcohol for the price of new burners. When I changed mine over, burners were only $7.00 & kerosene was only $.55/gal. (1978). You will need heat proof washers. Send Kerophile a privite topic. He makes good ones, and get at least 2 half thick washers for alignment of the control knobs. 2 washers min. per burner, one below the burner, and one below the burner tray.
     
  6. sailingcal21

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    Thanks for the info and about the quality of the stove that I have. I don't plan to convert away from alcohol, so will rebuild what I have.

    Now that you mention it there is less greenish and more yellowish flame then when I first started it.

    I didn't realize that the center piece was supposed to slide, guess that I don't understand the physics involved yet. I suppose that explains the pulsing flame and noise I get sometimes.
     
  7. dspearsy2k

    dspearsy2k United States Subscriber

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    Hi again; You mention 2 unrelated problems, pulsing flame and noise. The pulsing flame is caused by local sudden pressure increase inside the burner when fuel is flashed into vapor from a hot burner. The vapor requires more volume, therefore it pushes the liquid back toward the tank. The jet relieves this pressue increase and the fuel again flows toward the burner. Until the liquid fuel again hits the hot burner and the cycle repeats. To fix or lessen the pulsing you have to slow the feed into the burner. Normally this is done with fine mesh (50 or 100 mesh) brass screen tightly rolled and inserted into bottom of burner (tightly). This slows feed and resists backflow, balancing the internal burner pressure. Equals steady flame. Some experimenting may be needed to get the lengh of the roll right. To short = long pulse spacing. To long probably OK. I normallaly wrap screen around a piece of stainles wire to make removal easier. Some maufactures use a tiny jet in the feed line called a balancing jet. Second problem; Does the noise sound like a sputtering rocket motor in need of a tuneup? It's called underburn, and that's to be advoided. Do not depair, It's probably caused by the stuck sliding mixing tube. Fix the slider first and see if the sputtering roar goes away. A steady hiss is a fine running burner.
     
  8. hikerduane

    hikerduane Subscriber

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    I ordered a set of caps from A&H, Shirlene sent me a set of photos, so they look like mine.

    Duane
     
  9. sailingcal21

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    Got two burner rebuild kits from Shirlene. Installed one and flushed out the tank with fresh alcohol. Took about 4 rinse cycles to get most of the fine solids out of the tank.

    The rebuilt burner works much better. Thanks for the pointers, everyone.

    Any idea how many Btus I can expect from the burners?

    Scott
     
  10. threedots New Zealand

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    I have an Optimus No.5 that I had converted from kerosene to alcohol using one of those same burners.
    They are a very good burner that do perform well and reliably putting out a very controllable heat range.
    The maximun heat output might bring water to the boil a little slower compared to kerosene but it is hardly noticeable and the benefit of using alcohol is that it burns a lot cleaner. Also it is the same fuel needed for cleanly preheating the burner.
    The fuel consumption rate is a little more though.

    A word of caution: I believe the tolerances could be crucial between the sliding fit with the inner cap and the central mushroom part. Also there are 3 small raised points that keep these 2 parts slightly apart at the top so there should be minimal sanding of these parts only - only if needed. Too much sanding may affect the performance. John
     
  11. sailingcal21

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    Rebuilt the burners. Had a few issues however Shirlene and Bob helped keep me pointed in the correct direction.

    The right burner was a leaker but after a good Q-tip cleaning is working pretty well. It boiled an open can of water 2 1/2 cup (600 ml) water in about 15 minutes.

    The other burner is kinda weak. I can't open the valve very much without a flame out.

    Here's a link to both burners operating: http://youtu.be/AMVngSDqSQQ

    And here's the burner that flames out as I open the valve: http://youtu.be/Qwl9t0ec-A0

    Is the left burner not getting enough fuel?

    Let me know if I am not posting videos correctly.
     
    Last edited by a moderator: Jul 1, 2015
  12. Spiritburner

    Spiritburner Admin SotM Winner Subscriber

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    Although I appreciate you are not stating this as a fact, members may find this informative video & correction from the Berniedawg useful:

    Link to video
     
  13. James Brown

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    I have the same stove. unfortunately the previous owner let water sit in it. Dos any one know where I can get #209 burner kit for it online?
     
  14. Tony Press

    Tony Press Australia Subscriber

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    @James Brown

    Woops!

    I responded to your other post thinking that the photo was of the parts you wanted to replace.

    I see that the advice I gave is redundant.

    Tony
     
  15. Sean McClain United States

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    Thanks to all the contributors. This is a great post. It really helped me to get my 39a working. Unfortunately, I have located two cracks in my fuel tank with very slow leaks under pressure. I'm glad I didn't find out due to a fire under the stove! Is anyone aware of a source for a fuel tank? All of my other parts are good. I will contact A&H as mentioned above, but I don't see one listed on their website.
     
  16. Doc Mark

    Doc Mark SotM Winner Subscriber

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    Good Morning, @Sean McClain ,

    Welcome to CCS! Don't give up hope in finding a fuel tank for your stove. I know that I, and others here at CCS, end up with spare fuel tanks for that type of stoves quite often. If you stick around for a bit, and maybe post a request in the "Wanted" section, after you have a few posts built up, you may well find what you need. Hope to see you more here at CCS, and God Bless!

    Every Good Wish,
    Doc
     
  17. Sean McClain United States

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    That's great! Thanks @Doc Mark ! I will post it as you suggested.

    Sean