Dear all, I purchased a brand new Optimus 123 R last year or so, and from the beginning I wasn't convinced of its quality and performance. No matter what I - with the help of this forum - did and still am doing - its performance is still rather bad . What am I complaining about? Well, I start priming the stove with meths and light it, when it is hot. A nice blue flame appears, maybe with a bit too yellowish tips of the flame. Well, so far so good. After about half a minute the flame turns to yellow and releases much soot. It pulses extremely changing between a yellow flame like from a candlelight and a maximum blue flame with yellow tips. The frequency of this pulsing is some few pulses per second, not the helicopter-like noise which is typical for the 123 R. I am interpreting this phenomenon as a too quick loss of tank-pressure. First after the tank has become very hot the gas-flow is smoother and more constant resulting in better burning. Perhaps the jet aperture is too big releasing to much pressure and fuel? Unfortunately, there is not another jet for this stove available that has a narrower aperture, or is there? Even with a pot upon the stove acting as a heat reflector it takes some minutes until the stove stops its pulsing and has come to full power. When I try to simmer the stove the flame turns into the candlelight-like state again . I also have a Primus 71 that I have fitted with a new jet for kero-burners (aperture round about 0.30 mm) which works much better. It needs less pre-heating, is has a nice blue flame without yellow tips, it simmers perfectly without turning to yellow and so on. I have come across a Minipump and by the help of a kind forum member I hopefully will get the corresponding tank lid for the 123 R. I will then see if it works better, however, there's only slight hope . Any ideas? Any 123 R-users that made the same experiences with a new Optimus 123 R ? Thank you for reading and best regards, Philipp
You've probably already tried this, but the first thing I'd do is swap the entire fuel cap for a known good one. You've two opportunities for a slight pressure leak - the seal under the cap, or the internal safety release valve. If the seal is damaged or hard (I know it's new, but....) or the SRV is set up incorrectly, a constant slight loss of pressure might account for the symptoms you are seeing. A test you might try is as follows. Cool the stove in a fridge for half an hour. Equalise the pressure (i.e. release and then screw the fuel cap back on) and then plunge the entire stove into very hot water (ensuring the fuel control valve is fully shut beforehand). Any bubbles escaping from around the fuel cap (or anywhere else for that matter) will indicate a pressure loss (the high water temp will effectively pressurise the stove). Let us know...... Cheers, Graham
I have heard of a few new 123rs that did not have the wick pushed all the way up. Your symptoms are typical of either a overfull tank or a burnt wick. A wick not all the way in would probably have the same effect. When filling the stove keep it level. If you tip it you overfill the tank
Dear all, The stove is tight, no pressure relases through untight seals. I assumed that loss of pressure is due to a too big jet hole. The tip with the wick sounds promising. The tank is definitely not overfilled. I will try to screw off the burner and have a look at the wick (if the burner only would go off... I tried it before but gave up being afraid to totally ruin the stove ). Thanks for your input and regards, Philipp
I've gotten a few recalcitrant 123's apart by the expedient of clamping the burner in a vice after dismounting the burner bell. Do not put much pressure on the burner when clamping it in a vice, all you want is to hold it firmly. I usually put a folded shop towel in the jaws first then unscrew the fount. All that's needed is to loosen the fount, you don't want fuel spilled all over the place. It tends to annoy the Missus, don't you know? When you reinstall the burner put one or two wraps of teflon sealing tape on the threads and use light pressure, the tape is very slippery and the tank fitting can be burst by using too much torque. The valve stem should point to the "1" when in the correct position. I'm a great believer in teflon sealing tape when used with due caution. Like any other product it can be abused. Should this happen a stove or automobile carburetor can be converted into a paperweight in seconds. How do I know? Hard experience. When one bursts a carburetor body by screwing a tapered pipe fitting with teflon sealing tape on it too tight, one hears a sickening snap reminiscent of a wrist bone breaking. That sound can cause one to release a small amount of urine resulting in the unseemly amusement of one's erstwhile "friends". Those low-life scum know who they are and shall remain unwashed, unshriven and unburied. As is their due. Gerry
caps are interchangeable between the 123 and 71. If you have the minipump for the 71 its will fit the 123. The 71 wasnt designed with a pump in mind
It is vital to always equalize the tank pressure before running a self-pressurizing stove. I have had all sorts of odd symptoms that went away once that was done.
Greetings, What fuel are you using in your SVEA 123R? Doesn't sound like you are using Coleman fuel, which is what that stove was designed to consume. The new SVEA stoves are, unfortunately, not as well made as the older ones, and are not made in Sweden. Once manufacturing was taken overseas, the quality and reliability went out the window, as far as I can tell, and from everything I've heard. As an example, the new Apple iPhone 5, which is now being made in China, is being delayed yet again. This time, it's because of a strike at the factory that manufactures the iPhone, where workers are bitterly complaining about the quality control that is required in the making of this device!! They believe it to be TOO stringent, from what I've heard on the news. I do hope against hope that this is not the norm in Chinese-made products right now, and if it is, then we need to jerk all manufacturing out of that Country immediately, and learn a valuable lesson from this! Still waiting to see how that turns out.... In any case, what fuel are you using for your new SVEA 123R? Thanks, and God Bless! Every Good Wish, Doc
Hi Pillepalle, This is not an oversized jet. If it were, you would get a flame with large yellow tips, constantly. Try to remove the cleaning needle, and keep it out of the stove until you fix it and it burns happily with a perfect blue flame. Only then comes the time to put the needle back in. That way you have one less variable to worry about. As Doc said, make sure you are using clean Coleman fuel (or white gas) and nothing else. For starters, fill the tank only to 1/3 capacity. That way you have plenty of air to pressurize quickly. As a last resort, if the stove still makes you unhappy, send it to me. I promise it will make me happy. Enjoy! Yonadav
The cleaning needles on these are frequently mislocated during assembly. That can cause all kind of odd burning problems.
Hi folks, Thanks for your input. Of course I am using white gas ("Coleman"-fuel, however not exactly this brand, but something similar. Coleman did not invent white gas ). I tried the stove without the cleaning needle - no change in performance . I let pressure equalize before priming - no change in performance (my Primus 71 doesn't care!). No matter how full the tank is - no change in performance (my Primus 71 doesn't care!). I read through this forum and found quite a lot queries deailing with pulsing Optimus 123 Rs what makes me think about the quality of this stove . Yesterday I screwed off the burner stem in order to check the wick - looked ok, but I took it out and shoved it back into the stem until it went no more, since I had read that an inproperly set wick could could this not so unusual problem. Will light the stove today evening and let you know the results. Best regards, Philipp
Hi Philipp, Just a quick safety first suggestion. Having had the burner stem off and then back on it should usually seal OK. But as this is a white gas stove I'd personally check the continued integrity of the joint once reassembled. You can do this using the dunking in hot water test I described earlier in the thread. Some people have previously experienced small leaks once the burner stem to tank joint has been disturbed and used something like graphite paste as a sealant on the thread. Cheers, Graham.
Well, the thing with the wick was - in parts - successful. The pulsing has decreased considerably and the stove burns with a much more constant flame. However, the flame still has too yellow tips for my understanding, no matter if I lower or raise the burner plate. At least the stove works, but in this state it won't become my favourite one . Regards, Philipp
Well, Philipp, maybe this is the time to upload some photos, at last? And it seems that I will not be getting this stove, after all Yonadav
Well, after all, here are some pics: Burning full power with imho too much yellow in the flames: Trying to simmer the stove by turning towards "off": Best simmering result is acheived by pushing the cleaning-needle up towards or into the jet: I am clueless what to do in order to make the stove work as it should. Perhaps I simply should accept it as it is and use another one, when simmering (for real cooking) is needed. Best regards, Philipp
Hi Phillip. Thanks for posting the photos. 1. Assuming you are using good quality fuel, the images appear to show a flame produced from a fuel-rich mixture giving incomplete combustion. 2. This would seem to be confirmed by the fact that you can get a lovely blue flame by restricting the area of the jet aperture using the cleaning needle. 3. You can confirm that a fuel-rich mixture is the problem by loosening the "grippers" of the flame plate so that you can raise it once the stove is running. Do this using a steady hand and snipe-nose pliers, once the flame is established. If the flame turns blue as you raise the flame-plate you know that the fuel quality is not the problem, rather the quantity... 4. You can perhaps fix the problem by bending the support legs of the flame plate to raise the plate by a few mms. 5. If this does not work it suggests that the jet aperture is over-size and you need to obtain a new jet. Hope this helps, Keep trying. Best Regards, Kerophile.
Hi Phillip. I agree with Kerophile's advice about raising the flame plate. Have a look at the photos in this post which illustrate the effect of raising the plate - Link Regards, Terry
Hi George, Thanks for your advise. My comment in my initial post: meant that I already had gone through the "typical" procedures combined with a 123 R's bad behaviour (checking needle position, running the stove without cleaning needle, raising and/lowering the flame plate. I raised it to a really high position and the combustion still is incomplete. The jet is brand new! Certainly, it might be faulty, but I suppose it to be as it should. I wanted to exchange it against a jet for my Optimus 111 T, but there is a slight difference, i.e. I cannot screw the Hiker's jet completely into the 123 R - though I thought that both stoves had the same jet. Isn't it amazing - we spend hours with fettling and doing strange things to old-fashioned fire-breathers, we buy expensive spare parts and materials, we accept fuzzy ceremonies for lighting a stove - and can have a perfectly running gas-canister stove for a tenner instead, that offers us all luxury like simmering ability, easy use, no priming etc. ... No, we are not rationally behaving beings I believe . Regards, Philipp
ive had the same issues with my svea 123r on burning and simmering ... all i did was take out the cleaning needle and it fixed the issues with simmering and burning now i just need to get/make a pricker tool
I am going way out on the limb here. If the plate adjustment doesn't work, it may be that the pressure of the fuel vapor exiting the nozzle is a bit too low. Low pressue may not be entraining enough air for proper combusion. Yes, I realize low pressure would result in low volume of fuel but if it were mine, I'd check the filler cap gasket. Or maybe let it warm up a bit longer.
