I agree with the OP that the single jet for all fuels that Optimus uses (in the Nova and Hiker+ in my case) is a little too large for Kerosene to be burned without some smell or soot. Somewhat in Optimus's defense, they do recommend white gas over other fuels for those stoves. But for many of us, Kero is preferred for safety reasons (or economic reasons in some locations). Still, I am pretty happy with both stoves although I'd be willing to get rid of my Hiker+ since it offers nothing that a 111 can't do better IMO. @Mark Layman , I appreciate the tip on an alternate jet.
I have very good experience with kerosene on my Nova. But I have never got any 111T to burn clean with kerosene. And that is the 1-jet-fits-both-kerosene-and-whitegas models I have tried. Phoebus 625 is another model I struggle to burn kerosene clean, even with dedicated jet for kerosene.
Well, I had to try kerosene (not my favourite fuel at all) in my Optifuel, with factory burner cap and with Berniedawg cap, and in my Nova. Comparing them to a well behaving Høvik Primus 210. This was the set up: The Nova is in a Trangia 25. I LOVE how smoothly the Nova adapts to the Trangia and what a great stove they make. I have been using a quiet burner in the Nova, the Korean "discuss" style. I would not recommend it to anyone, with kerosene it did not burn well at all. But with the factory burner plate it did quite well, boiled water fast and with no soot on the kettle, and made cofee on simmer with a Bialetti with no problems. Flames where mostly blue but with som yellow flaring without a kettle on top, with the kettle its hard to say using the Trangia, but it looked all blue down there in the depths of the windshield. The Optifuel had more yellow in the burn pattern, but again no soot on the kettle. With the Berniedawg it burned very clean and blue on simmer, more yellowish on full, but then again I think the cap add some colour to the flame pattern. It eventually started to underburn and I don not bother to investigate that problem further. With the Berniedawg silent cap: With the factory burn plate: The reference, Primus 210: I`m not sure I use the best kerosene, it is recommended for kerosene stoves, but all I can find regarding what it actually is made up from is whats on the label: "Petroleum" and "Hydrocarbons C11-C14" @afoton; its "Kemetyl Fritidsparafin", what type ar you using? Tron
Fritidsparafin is my prefered type. But actually I have not seen any difference with good burners with different kerosene types. I use the one I find. But with 111T and 625, there is easy to smell the different flavors of different kerosene types.
That’s exactly the kind of yellow I get with “good” kerosene. It’s just not optimal with that much yellow in the flame and will go away with a smaller jet. Maybe Optimus could offer a specific for heavy fuel orifice as an accessory in the future. Or, the XGK preshaker kero jet for those that really want a clean burn with no yellow. Thanks for the pics @Tron. Now I don’t seem like such a crazy person. Ha.
You never did. A bit meticulous maybe :-) No, I agree, neither my Nova nor my Optifuel burns kerosene with a perfect flame, but good enough to cook without messing up the food or the utensils. I think you're absolutely right, ithey can not burn perfectly with all kinds of fuels with just one jet. But I also think that they where never ment to, they are ment to burn white gas perfectly, canister gas well and still being able to burn kero, diesel etc. I never use a kerosene stove inside because they always smell a little, so a few yellow specks in the flame pattern does not bother me at all. Tron
My view as well. The Optimus Polaris Optifuel were intended to be an outright Primus Omnifuel killer - for the present day user crowd. (Not a perfect kerosene/paraffin burning design for us kero religious purists.) And as such it has been a true design success - it beats the Omnifuel hands down: No fiddly jet exchanges. No fiddly cleaning process. A fraction of the pre-heat alcohol volume needed. Designed to easily burn liquid canister gas (due to the canister stand design). Etc etc. And the PolarDawg2 silent burn hat is a better design as well. It stays put in the burner cup... So no wonder they designed the Polaris the way they did. YMMV of course... /Odd
I just tried out burning kerosene in my Trangia X2 Multifuel (which is just a modified Primus Multifuel) using the gasoline jet (0.32 mm) instead of the smaller kerosene jet (0.28 mm). The flames were slightly yellow at the tips, there was a faint smell of unburnt kerosene, there was slightly more soot on the pot, and the boil time for one liter of water went from 8 minutes 30 seconds to 6 minutes 30 seconds – a 30% decrease. This is consistent with the fact that the gasoline jet is about 30% larger. I also noticed some slight pulsing and sputtering with the 0.32 mm jet. Trangia/Primus recommends the 0.32 mm jet for white gas and LPG and it seems to do reasonably well with kerosene. I'll bet the Optifuel jet is simply a jet optimized for gasoline. "Single jet technology", my butt.
Jet is not only parameter... If Optifuel is able to evaporate (+enough air to mix good mixture for clean burning) kero more better than Primus Multifuel then it should work ok with single jet.
Jet size isn't the only parameter, true, but let's look at an Optifuel and an Omnifuel burning diesel, shall we? (The images are shamelessly stolen from a couple of Youtube videos I found) I'd say that the Optifuel might benefit from a little less fuel in the fuel-air mixture and an easy way to accomplish that would be a smaller jet. I have found images of the Optifuel burning kerosene and while the yellow tips in that case are far less extreme, they are similar to the result I get with my Trangia X2/Primus Multifuel and Primus Omnilite TI using the 0.32 mm jet with kerosene. Edit: I just checked the Optifuel manual: the "injector" size is indeed 0.32 mm. I think the oddly designed burner bell is supposed to increase the air flow. In theory, this should keep the fuel-air mixture from getting too rich.
@Mark Layman , I like your idealism and meticulousness. I realize that I'm not a stovie person. I've once owned a Primus Omnilite Ti until I experienced that the flame control is too sensitive, and the flame sometimes not consistent. I sell it. I only need 1 multi-fuel stove at all times. I did a little Google-ing research and landed my choice to MSR Dragonfly. I modified the hose to use a Lindal screw type, so I can use a pump with Lindal connector from Primus/Optimus/BRS/Bulin and can also burn gas canister, even if the flame sometimes goes out suddenly, even in liquid feed mode, I realize that the DG jet may not suits to burn LPG. I haven't modified a jet to enable MSR Dragonfly to burn LPG, and also haven't drill another jet to burn alcohol. It is still on my plan though. But just recently, I cannot unscrew the jet on MSR Dragonfly, no matter how hard I try even with help of WD-40, still, I can't unscrew it. I used to be able to unscrew it. Now it feels impossible. I've landed more scratches on the jet every time I try my hardest to unscrew it. It is kind of frustrating. What is a better stove than Optimus Polaris that can burn white gas, LPG, kerosene, diesel, petroleum/gasoline, and paraffin? Does MSR Whisperlite Universal will be a better choice than a modified MSR Dragonfly? Best IM
My buddy uses an Omnifuel and I guess that I'll have to borrow it sometime just to try it on kero now. I have the Omnilite and it loves kero. My Nova likes anything especially my 75/25 amish mix. @Mark Layman One thing that I would like to interject into the equation is the actual fuel. Here in Florida kerosene comes in 100°F, 124°F, and 154°F flash points. Actual 154°F kero is hard to find undyed, while 100°F & 124°F being the norm. The flash point really determines how much pre-heating a fuel needs and thus how easy it is to get a nice blue flame. I try to run most of my stoves and lanterns on a minimum of 124°F flash point since the 100°F is not safe in a flat wick lantern or my aladdin lamp. Once I can get my hands on some Jet-A fuel it will probably be all that I use in the future since I prefer buying in bulk. Omnilite using the factory kero jet on 124°F kero
Related to this discussion, my new Nova burns kerosene very well, clean and blue. I do keep two flame plates available. The one sitting lower on the burner I keep for white gas. The one that sits higher I keep for kerosene. I burn the high priced stuff in my stoves, K1 from Home Depot. My manual implies a clear preference for burning kerosene in this stove.
I think part of this is from the pressure in the bottle. I found that on the Omnilite Ti that if the bottle is very pressurized then the lower end of flame control tends to "bounce" as you bring it towards a simmer. At low fuel bottle pressures it tends to have a very good response on the low end but the upper end is lacking even as the valve is opened all the way up. Keeping an intermediate level of pressure gives decent flame control towards simmering rather than having to overshoot by bring theing stove down to the point it almost goes out before releasing the valve where it "bounces" back up. You may want to start out by very slowly enlarging the jet with a series of wire drills and testing it each time for gas feed. I found on stoves like the Omnilite Ti that the gas jet is .36mm for the opening and that on the Whisperlite Universal the jet is raised to reduce the amount of air being mixed but I have no idea about the diameter. On my Soto Muka I found that while it would run on butane on the white gas jet (~.35mm) but it would have some underburn when just above a simmer. I enlarged mine to .406mm for around a 130-ish% increase in surface area for the opening and it works well. @presscall and @teckguy_58 opened theirs to .45mm and have excellent output along with blue flames: My 'ultimate' Soto Muka outfit For the Muka I gradually stepped up sizes on wire drills, at first starting at .368mm then tested it and found underburn still occurred, then I moved to .406mm and found it to be a good compromise as the Muka is an overpowered stove for even 10" and larger diameter pots when it comes to white gas output. The next wire drill size up for me would be .457mm so I did not go for a larger opening as I wanted a leaner mix. You may want to try this with your Dragonfly by slowly going up the drill size and doing some test burns. As for alcohol: The same applies, walk up the drill sizes. For reference I found the Whisperlite Universal (not the International! the jets are different) and Omnilite Ti worked okay with a 1/32" (~.79mm!) jet for kerosene for isopropyl alcohol which needs more oxygen than ethanol and methanol and I get it to run on even 91% and down to 80% in the WLU. Do not try making such a huge jump like this and instead walk up the drill sizes one at a time or you'll just end up with an oversized jet. The international needs a smaller jet size than the WLU when it comes to alcohol. You may want to try to use something to press on the top of the MSR tool while using a wrench on another while the stove is secured from movement. I found that my XGK EX's jet was very, very secured and I could not release it with hand pressure but by using a wrench on the MSR tool to give some extra torque and a good amount of downward pressure that I could get it free. I don't have a Dragonfly but I have an XGK EX and Omnilite Ti (with a BD cap and also the Primus silencer) to compare against. The WLU does not burn kerosene or charcoal lighter fluid (in the case of the Omnilite Ti, I drilled my kerosene jet for alcohol and I'm waiting for a replacement) as well as the former two and has more of the kind of sweet but stinky odor produced by burning kerosene more than the XGK EX and in the case of CLF it tends to be stinky unless I add in enough white gas or add kerosene in combination with white gas. I experiment with fuels so my kerosene may have been only around 80% kerosene and the 20% being a mix of alcohol, charcoal lighter fluid and white gas plus a little water from the alcohol. I can't imagine trying to burn diesel in the WLU as the generator takes in less heat and it doesn't have the burner bell pouring heat into the base where the jet is mounted after seeing videos of diesel being burned in an XGK EX where the jet is very, very yellow (I'd have to check if a smaller jet is being used...). I also bring up charcoal lighter fluid as it seems to have the high flashpoint of kerosene but the energy density of white gas so it tends to be very hard to burn in stoves unless I add some white gas to it. In my experience the Omnilite Ti with the Primus silencer is surprisingly capable of burning straight CLF without a bit of odor which may mean it is very capable of burning kerosene better than the WLU so long as the stove is preheated sufficiently. I do have a Polaris coming in at some point (backordered...) and I have some XGK jets that I want to try in it so I'll report back if it burns kerosene any better. I hope this information is useful for any experimentation you may try out on your Dragonfly and/or any future stove acquisitions @Iming Muslimin
Does that mean, a mix of 10cc 96% FGA/PGA to 90cc kerosene will be dangerous to be used in a multifuel stove, says Primus Omnifuel-Omnilite Ti, Optimus Polaris Optifuel?
Multifuel stoves are built to be safe with fuels of higher volatility - if it can burn gasoline safely, even low flash point kero will be a doddle. Wick appliances are a different matter entirely.
So, it is quite safe to burn a fuel mix of 80% kerosene and 20% alcohol? I read an article that describes the common use of a mix of kerosene and alcohol for daily cooking activity in India. It is quite safe. From your explanation, you recommend a Primus Omnilite Ti, and it has more advantages than MSR WLU. It will be exciting to know about the experiment you'll do with Optimus Polaris Optifuel
But, I don't think I can tolerate that behavior from Primus Omnilite Ti. The MSR Dragonfly, however, burns rather stable when I give it up to 60 strokes. I have given MSR DF an 80 strokes at once, it is rather stable, blue fame with white gas or LPG, adequate to cook longer, but it was anxious for me, I'm thinking about the risk of the exploding part, maybe I'm just being too paranoid, right
