Gasoline versus Kerosene - Optimus Nova

I am new to the forum but I could not find anything using search.

I find my brand new Nova, to me, works better on kerosene and I prime using alcohol. It takes longer than gasoline to prime, as expected but with kerosense it is either on or off. The quality of the burn is similar. Gasoline produces carbon that gets spat out and has blocked the jet several times. A filament of carbon can attach to the top of the jet and block it. I can see it ejecting small bits of carbon on gasoline especially on a dirty restart but it seems to be a feature. I would have thought kerosene would be dirtier but the opposite seems to happen. I haven't used Shellite yet just unleaded but unleaded ran clean in my Soto Muka so I don't see an issue with regular unleaded we get here in Australia.

I'm curious which is why I am on the forum. It is interesting to read some of the threads and the depth to which people investigate and deal with these stoves.

 

@InspectHerGadget , try shellite and use that to compare with kero. Unleaded has lot of additives which are worse than useless in stoves.

 

Optimus Nova?
Kerosene for me. Mines a Brunton.

 

I will try it out and report back sometime. I have the stove setup outside. You may well be right too. The Soto Muka loves unleaded but maybe the point of ignition is not on top of a tiny orifice like on these stoves. It is the feathering on the orifice and also you get small flakes or filaments of carbon thrown. I've seen it on videos too where they turn the stove up and it rains this fine carbon almost like small sheets. Carbon was originally used as filaments in light globes by Edison and that is another problem. The carbon continues to burn as it absorbs fuel and so continues to burn after the fuel valve is closed often right on top of the orifice.

Kerosene has quite different properties...it is off or on...less volatile...if it goes out it creates a black cloud which smells but doesn't cause any sooting in the stove.

Maybe Boeing was right not to go with gasoline???

 

Ha. I have a Katadyn! Yes, Optimus Nova. I made a mistake. I don't think I can change the title of the thread.

The Nova is a great stove. The user manual does recommend kerosene...which surprised me. They said to use the fuel to light the stove which is obviously ok for gasoline but not kerosene. I use what we call here methylated spirits which burns extremely well. It is ethanol with denaturants added so you can't make cocktails from it...except molotov ones.

 

With a wick in the priming tray you can prime with kerosene (outdoors).
A wick improves priming with gas or meths too.

 

Thanks for that. I had an optimus 8R and it didn't have a wick for the lighting bowl...mostly we used alcohol or metaldehyde for lighting.

I ordered a parts kit for the Nova that includes a wick...I might need it in another 3 years from now? I imagine the Nova will go a long time between services if you use clean fuels. Can you just make up your own wick from other materials? I can't imagine the material is particularly unique or rare.

Shellite here is twice the price of kerosene so kerosene is still the preferred fuel and less combustible. One youtuber said that kerosene is better for o-rings but both petrol and kero lubricate although maybe kero a bit more...definitely greasy.

I'm getting a second hand dragonfly this week I think. I would like to run it on kerosene but I need a different KC jet for that. It seems the only way to get that is to order the expensive expedition repair kit. I'm here in oz too so things are harder to source.

 

Making up some spirit-cup wicks.

 

@InspectHerGadget

Try the DragonFly on kero: mine certainly burns kero cleanly with the DG jet. The kero jet is DK.

On the o-ring situation, a viton o-ring kit from Super Cheap Auto or Repco will cover all you need with either stove (I would hope). The exception is the tiny DragonFly pump fuel outlet o-rings. They are a safety factor that do nothing if you religiously close the pump valve.

 

Thanks for that information. Interesting that it can burn well with the standard DG jet and thank you for the suggestion on the o-ring kit. I probably have one of those already or parts of it I haven't used.

 

I'm testing the Nova with Shellite...still not as good as kerosene for boil times but not bad. The Nova seems to run well on unleaded (possibly a bit dirty but maybe my missteps restarting a hot stove), Shellite and Kerosene. Kerosene is likely to be the winner due to price and soon I will get my Dragonfly and will try that on kero as well and see how I go.

 

This is a useful reference to different fuel types. I posted this on another thread but it is more relevant here.

FAQ - Fuel Efficiency - technical details

I've been running this on kerosene and gasoline alternating and cooking a few things as well. It is outside on our outside table.

It has been a lot of fun and these stoves are just so good for cooking with great control over the simmer. Colour me impressed with this stove. Everything just works and works well and all the fittings are very high quality like the fuel line twist connector to the bottle.

I had one concern with the seal on the bottle but it turned out to be nothing.

I did need an explanation for why kerosene produces more energy by easily 20% and the energy produced per ml is 22% more for kerosene. It may not sound important but for doing toast it does make a real difference. On gasoline, the toasting is really just barely adequate whereas on kerosene toasting is pretty good. The Soto Muka I had has more power but it had poor simmer control so it made an untimely exit from my ownership.

If anyone is thinking of the Nova...just buy it unless you want to use canisters as well, then buy the Optimus Polaris.

I still have my Optimus 8R after 46 years but I might need to post a few pictures and get some advice on that as it needs a complete overhaul and it may be better to sell it to someone who enjoys collecting stoves (and repairing them).

It is interesting how Optimus has done such a good job of running kerosene and gasoline or shellite on the single jet...possibly it isn't as efficient but it burns very nicely on both.

I did have an issue using unleaded but it was the fuel. It would just unexpectedly play up so I switched to using Shellite which is without additives and it ran fine. I think additives were coming out of the fuel and affecting the burn in real time. I could switch to another fuel without cleaning the jet and it ran fine.

I prime with alcohol on kerosene and it is a slight inconvenience but kerosene has more grams of energy in a bottle and burns clean and produces more heat and yet goes down to a low simmer extremely well.

The manual recommends kerosene and it is my favoured fuel on this stove but Shellite is convenient as you can prime with it also. I probably will switch at times between the two fuels and I now have an extra Optimus green bottle so it would make it easy to switch fuels.

I also got the full parts kit for this stove but I can it taking a long time before I need to replace o-rings and the like but it is good to have them. I had to order the parts kit from Japan and it is due to arrive shortly.

I find here in Perth Western Australia...I end up ordering stuff from overseas mostly although I got the Nova from ozbackcountry.com.au and they seem good to deal with.

 

I'll second the Dragonfly running fine on kero with the DG jet. It seems to loose a little of the low end of simmering without going yellow, but burns very well at the medium to high settings. Conversely, gas does just fine through the DK jet... better low simmering and it needs just a little more bottle pressure to get the maximum flame up to what you get with the DG jet. This all makes sense based on the smaller DK jet orifice size, but it's surprising just how well the Dragonfly does across the range of fuels.


Dragonfly hard at work with white gas through the DK jet.

 

I picked up one of those Dragon Fly stoves some time last year, i'm very impressed with the simmering capability.

 

I am pleased to see that the Dragonfly can burn kerosene well but obviously having the proper jet helps get the best result. If I ever bought one it is good to know it has some tolerance to using either jet for either fuel, although that would be expected.

So far the Nova seems to work equally well on either fuel right down to low simmer.

My only issue so far is that unleaded after burning a fair bit of it, I concluded did not work as well as Shellite or 'White Gas'. I think that unleaded is going to vary in additives and quality so it is difficult to say if unleaded in Perth is the same as unleaded elsewhere. Shellite though works well and the BTU energy difference between kerosene and Shellite is explainable by S.G. differences but does have benefits aside from safety. Unleaded seems to drop additives in real time during the burn that cause issues...the only way I can explain it as it doesn't appear to be causing blockages.

I could use kerosene for priming but would rather use alcohol as it is so nice and clean...no soot on my stove. It is just not quite as convenient as using fuel from the stove.

If I got another stove it would be the Primus Omnilite Ti or the MSR Dragonfly. The only reason I would get another stove is sheer curiosity and for the sake of comparison. I do love gadgets and stoves are interesting things...simple but maybe not as simple as I thought to start with.

The Nova seems to have advantages over the Dragonfly such as ease of emptying the fuel line, a single jet for multi-fuel and a longer and more flexible fuel line and it is more compact as well. I am aware though that the only way to really compare two stoves is to own both and use them for a period of time and the MSR Dragonfly is 100x as common as the Nova and has a loyal user base...I think also the ability to burn canister fuel is kind of pointless and neither stoves do that.

 

I will tell you how I go. I have a brand new Dragonfly arriving tomorrow...call it a brain fart but curiosity got the better of me.

I have been using the Nova every day...yup just for fun. It is still Winter here in Perth and it is kind of nice doing a few things on the stove. I've pretty well gone over to priming using alcohol whether for petrol or kero. I probably favour our unleaded due to price. I have a few issues with strange burning issues where it seems to struggle sometimes on petrol but I give it a clean and it runs again just fine. It is hard to know whether it is just some feathering on the jet or something depositing from the unleaded petrol or both but most of the time is OK. I do get a bit of chugging too but that too comes and goes and decreases with pumping it a bit more. I will be interestedi n the DF as the DG jet will be bigger so wondering if it will run better on petrol. It may be that all these liquid fuel stoves have their quirks. Kerosene runs noticeably hotter than unleaded as I can tell when I do toast on the wire stand. I have two bottles, one for unleaded, one for kero so I can swap the fuels easily. I really need a filter funnel and it seems Coleman might be the best but I have to order it online. We are on the edge of the universe here in Perth although Amazon and Ebay make it easy enough to get stuff although you have to wait.

I feel sometimes that I am too much of a perfectionist when it comes to these things. I could probably do with some DC current between the temples...LOL

 

Yeah, that's the problem with this hobby.

The number of stoves you want = (the number of stoves you have + 1)

Keep us posted on how the Dragonfly compares.

 

Well, the DF goes like a bomb from the first second...in a good way. One minor issue is part of the wick is not quite in place at one end. It looks like some sort of wire is used to wrap it in place...primitive but effective...sort of. I tried turning over the bottle to turn it off but...no it doesn't work. Oh, well. The MSR is a bit primitive in that respect...not absolutely perfect...LOL.

The other issue is that the Nova has an issue with not retaining or getting to pressure I think. I am putting away the DF temporarily and getting the Nova going again. It isn't leaking fuel obviously as I would soon know about that. It may just be an issue with the leather cup so I will lubricate it a bit more and see what happens.

The DF might be a bit louder but not a lot in it but it just seems to get to maximum intensity burn and stay there and it was easy to pressurise but this may be normal and the Nova should do this too but isn't.

...leather cup is the problem. It isn't clear why it is leaking although it does have a nick in it. I fortunately had the spare parts kit with a spare leather cup in it...carefully fitted it. It would be easy to damage getting in and out so it is another feature I DO NOT LIKE. These stoves should be bulletproof. My bet is customers would squeal if they got a rubber o-ring rather than leather but an o-ring is the modern and effective solution and leather is the 100 year old pre---o-ring solution. The pump on the MSR requires less pumps even now with the new leather cup in...the MSR pump just works better. I hate to say it but this is true and I found out the hard way as have others with this pump.

Once I replaced and pressurised...much happier with the stove...of course!! I think the problem happened slowly then maybe suddenly so I couldn't ignore it any longer. I'm afraid to touch it now but I will get a warranty replacement to cover this.

 

O-rings get unhappy when they're cold. They can fail completely when cold and not lubricated. You can't fix a broken o-ring. A dried or even frayed leather cup can usually be reconditioned in the field to work after a fashion, or a new cup can be cut out from some other piece of gear.

....Arch

 

A review by outdoor gear lab complained that they had to replace their leather cup as well on a new Primus Omnilite.

Primus Omnilite TI Review.

I guess all devices have a problem but I'd be happier going out with the MSR pump and a spare o-ring after this experience.