MSR WhisperLight alcohol mod

I got my MSR WhisperLight International camping stove two decades ago for my first proper backpacking tour down the Kungsleden from Abisko to Saltoluokta. Unfortunately somehow I managed to buy some perfumed lamp oil in the little supermarket in Kiruna and ended up with a really hard to prime and very unhappy burning stove on my tour.
Newbie luck I guess. At least the stuff smelled quite good. 😀
To add insult to injury, several prior hikers left bottles of Trangia alcohol fuel in the shelters along the way for hikers in need (like me), but despite several desperate attempts the WhisperLight outright refused to burn that stuff.

The WhisperLight alcohol mod:
Back home experimenting started and soon it became clear why the WhisperLight doesn’t accept alcohol as proper fuel. It gets too much air in relation to fuel to burn alcohol. The cure for this unfortunate behaviour is rather simple. You just have to be able to adjust the air intake to convert your WhisperLight to a happy burning alcohol stove without sacrificing its ability to burn petrol or kerosene.

MSR tells their customers in their stove FAQs the WhisperLight International wouldn’t burn alcohol. Out of the box it doesn’t, that’s right, but there is an easy fix that probably would not only please a lot of Scandinavian users and will cost only penny’s.

brass tube, inner diameter 16mm, height 12mm, cross hole diameter 8mm

A short stainless steel, brass or copper tube with a cross hole and preferably a short handle for adjustment, is all that’s needed to convert the MSR Whisperlight series stoves to accept non toxic and clean burning alcohol as proper fuel. Just prime it as normal, close the air intake 3/4 and slowly open the valve. Some adjustment to the air intake might be needed at first, but then is will snarling quietly along burning with a blue flame. Running on alcohol the WhisperLight will use a bit more fuel than you’re used to with petrol, though.

The MSR valve mod:
Adjusting the WhisperLight to simmer regardless of fuel is, ehm…, let’s be polite and say it is reluctant to burn other than full force or not at all. Finding the right spot at the valve somewhere between 1/50 to 3/50 of a turn (eg. between snarling full force and a quietly dying flame) can be a bit nerve wrecking after a long day hike with an impatiently growling stomach.

MSRs offers ‘help’ for this problem in their FAQ:
‘Our award-winning DragonFly™ stove has a fully adjustable flame, which makes simmering a breeze. However, with other MSR liquid fuel stoves, the most efficient way is to run the stove with extremely low pressure in the fuel bottle. A couple of pump strokes in a half-full bottle are optimal.’

Yeah, right! First you need high pressure in the tank to start the stove and heat your pot in a sensible time and then you have to release that pressure to simmer your food. Anyone else who is a bit reluctant to release pressured petrol fumes around a red glowing surface inside a tent in the middle of nowhere, while cooking?

valve screw with beveled end

The fix to this stupid design flaw is so simple it should be embarrassing for MSR that they didn’t get it right in the first place a quarter of a century ago:
Get a fine file, take the aluminium valve screw out of the pump and bevel the first few millimeters of the cylindrical end to a conical shape. Use some caution, make sure it stays round while you bevel away and leave some millimeters cylindrical in front of the thread.

After this tiny modification to the valve the Whisperlight and other MSR liquid fuel stoves are vastly more precise to control for easy simmering! I still remember the happy face of a long time Whisperlight user when he fired his stove up, after I applied my little fix to his valve. Luckely for me he was the guy with the espresso machine and offered me a mug of rather exquisite coffee when I crawled out of my tent the next morning!

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24 Responses to MSR WhisperLight alcohol mod

  1. Alex says:

    Great mod you worked out. Thanks. I will get a spare valve screw and try it out!

    Thanks again. Much appriciated!

    Cheers

  2. I got the new WhisperLight today, first thing I did was this alcohol modification. Thank’s for making this modification info available! This mod allowed me to cook my first meal with 91% Isopropyl.

  3. Max says:

    Where did you find copper tubing with a extension/holder? Or did you manufacture your own? I could cut some copper tubing and drill the proper size holes, however I don’t have a blow torch to weld a handle onto it!

    • I made the tube myself by cutting a brass tube to the right lenth, drilling the holes and soldering the handle on.
      If the tube has a thick enough wall you may just drill a hole, cut a thread and use a long screw with a nut to lock it in place…

  4. Does this mod still work with the new stoves and the new style control valves? I was thinking about mine and it now is made with a red flag style handle on the control valve. Something like this… http://tinyurl.com/nzehzgu Thanks so much – great mods. I am going to work on this one first as I have an abundant supply of white gas, but the other one may be fun also. Cheers.

  5. Yigal Barkan says:

    The simmering mode sounds like a great solution. I considered buying the Dragonfly only for that.
    Unfortunately the explanation was far too condensed and articulate for me to understand. will you be able to add further detailed explanation (additional pics would be great) about the modification made?

    Thanks for being innovative enough to solve a problem with an elegant solution!

  6. Anthony Cole says:

    Outstanding Mod!..Have owned my whisperlite since it 1st came out and those 2 things were my only gripe. Took me maybe 20 min total for both. Thank You and well done!

  7. Mike says:

    Hey there, thx for the info and research. Saw a video where a guy mad a bigger hole in the jet and he was able to burn Isopropyl with his MSR Whisperlite. Was doing some research on how isopropyl can damage the MSR aluminium bottle, but with no real answers… anybody got any clue? Thx 🙂

    • Marc says:

      Isoprophyl or other alcohol will corrode pure unpainted aluminium bottles over time. Just get a painted aluminium bottle from Sigg if you want to keep alcohol in them.

      • Mike says:

        I was curious due to the MSR statement: “No, MSR stoves will not burn alcohol, and alcohol will damage MSR Fuel Bottles.” Wiki and other sources state, that aluminium containers can be used to store Isopropyl: “Aluminum is suitable for non-anhydrous isopropyl alcohol. However, anhydrous isopropyl alcohol will rust aluminum, especially at higher temperatures. Concentrations below about 95% can be stored in aluminum tanks at normal temperatures.” I own 99,5% Isopropyl and if I manage to mix it with distilled water to about 94% it might be store-able in the MSR bottle right? The other solution would be then to paint the inside of the MSR bottle with a layer of isopropyl resistant paint. Does isopropyl damage the rubber O-rings in the MSR fuel system?Thx in advance 🙂

  8. Bryant says:

    Greetings
    I have been wrestling with several of MSR stoves which have slightly different valve stems. I’m curious to know exactly where you modified the taper. It’s unclear with just the after pictures. Is it on the large (aprox 4 mm diameter threaded portion or did you increase the taper on the small (maybe 1.5mm) nipple at the very end? I am uncertain where the valve actually seats.
    Thanks
    Bryant

    • Marc says:

      Hi Bryant,
      Its the small approx 1.5 – 2 mm part at the very end of the valve scew. It was cylindrical and I’ve made the front part slightly conical.

  9. Bryant says:

    Thanks Marc
    I am about to turn mine down however itnis a newer style valve stem. I’m not certain what surfaces actually seat. It seems that the small nub at the end controls some flow but perhaps the larger surface at the end of the threads might be a shut off. What’s your take on that?
    By the way, really nice Trike. What type of battery management system are you using. I didn’t catch it in your blog. I have worked a lot on a Twike here in the states.
    Thanks
    Bryant

  10. Marc says:

    Hi Bryant,
    Just bevel the tip of the 2mm diameter end. You are right, the 2mm nub insets in the hole in the pump, controlling the fuel flow (controlling it badly, thats the whole problem) and the flat surface closes the valve. When the tip is beveled, the fuel flow gets more precise when turning the screw.

    Thanks! I really love my Sprint. It’s quite fun to ride.
    I use Sony Konion US18650V3 cells in my battery packs. Since these cells are not prone to voltage drift, I don’t use a BMS.

  11. Aaron says:

    Hello,
    I have a question about the valve mod. I have a newer whisperlite and the valve looks different than the picture above. The nipple on the valve I have is longer and has some ridges on the end, will this mod still work on the newer valves?
    Thanks
    Aaron

  12. zach says:

    I tried both of your suggestions and the air regulator is pure gold, made mine with a little coper pipe and I use a pliers to adjust the airflow manifold when its time to burn ETOH. Mine’s a little rudimentary but it works all the same. As for the beveled screw for controlling the flame I’ll have to do some more grinding. I think the first pass I made didn’t make much of a difference. Thanks for your Ideas and explanations!
    Cheers!
    Zach

  13. peetiez says:

    I tried sanding down the valve screw on the new style valve and I found that there was actually a bit more control than previously.

    In the last it was very sensitive and was a very rapid transition from off to blowtorch. After the mod I found that there was a smoother transition although it was still very sensitive.

    Another thing I found was that during priming was the valve was very sensitive from tightly closed and a little movement resulted in alot of fuel coming out.

    I grinded down the ~3 rows of thread at the narrower tip and rounded them off.

  14. Phil Cyr says:

    Thanks for the instructions! I’ve completed a alcohol mod on my new style whisperlite international, the one with the steel plates instead of the wire pot support. The new whisperlite has an aluminum core that is just the right size to fit into a copper 1/2″ coupling. I got a coupling and cut it shorter, leaving a tab. I folded the tab out to make an attachment point for a handle. Instead of drilling holes I cut two slots down from the top. Works great!

  15. darknewt123 says:

    Hiya,

    i am going to do this mod, problem is everyone is telling me they don’t do pipe to that size!! Do you know where I can get some from?

    Regards,

    • cerium136 says:

      A 1/2 inch coupler without the centering indentation fits perfectly. All I had to do was cut about a quarter inch off and cut some square slots for air flow.

  16. Andres says:

    Hi, wonderful modification! Do you have an idea how to make MSR XGK II to accept ethanol as well? Bought one by accident (thought it could use ethanol) and do not know what to do with it:)
    Best Wishes, Andres

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