I have a 2012 or so whisperlite international that has been working great until my last trip. On the last day it started burning kind of yellow and gets more yellow the longer it burns. It also sounds like the flow is a bit erratic, almost sputtering but not quite. I have taken it apart and one by one have replaced every o ring in the pump, the pump cup, check valve, the red pump outer ring, cleaned the jet, cleaned and flushed the line several times, even replaced the jet as I had one in my field kit plus bought new fuel. It’s the UG jet with MSR white super fuel. Definitely it is primed correctly just like I have done for a few decades. it starts mostly blue with a few yellow flickers then gets a sort of yellow halo over it that gets more yellow the longer it burns. It is summer, air temp is around 20. It’s not windy. I have tried more pressure, less pressure, and no difference except maybe worse with more pressure. What could be wrong? What else should I try?
You don't say that you removed the fuel line cable. It seems like you lose heat transfer. Is everything tight?
Yes. I removed the line cable, scrubbed it back and forth, wiped it, flushed the line several times then repeated it all again. I dismantled the cup and jet again, cleaned them off and tightened it up again. Seems to seat fine.
If there ist some water containing traces of salt in the old fuel, the water may explain the erratic burning of the stove. Saltwater is able to give the flame a yellow colour. Salt (Sodium chloride) contains sodium, which give this yellow color, when hot. Seawater contains also potassium, which can change the colour a little reddish yellow. The same happens, when boiling potatoes with salt in the water and some water spills into the flame. If your stove runs well with the fresh fuel, everything is fine. The residues of salt will disappear over the time and the colour will turn to blue again. Search for "flame colouration of alkali metals" if you are interested in the theory behind.
Have you taken off your burner cap and cleaned the flame rings and the tube and bell. Looks to me as the burner bell is getting redder so is the flame. Maybe the rings are squished down too tight. I’d try cleaning from the jet up. No Whisperlite expert by any means.
@Brenda I see the orange flame all time when burning a freshly cleaned stove and bare metal surfaces, especially steel parts. It will eventually go away.
Good job rebuilding your stove and pump! You have ruled out potential fuel issues, leaving little remaining to check. I suggest putting a big pot of water on to boil. Then check bottom of pot for soot. (And you have hot water for tea and a meal.) Odds are good you won’t see much, if any, soot on the pot. As HunterStovie described, for some reason freshly cleaned steel surfaces do this to flame colors. It will eventually go away. But if you see lots of dirty soot, now you know there’s an air restriction. Take the burner rings apart. Look for anything restricting the air intake and rings. Good luck with your troubleshooting! Let us know how it goes.
Thanks! As you and @hunterstove suggested, it seems it is just yellow but actually burning hot. I made tea and no soot. Had to do a second pot to be sure. lol. Thanks for all of the advice and tips. I will be interested to see how long this lasts. I appreciate all of the trouble shooting from this site!
I did just finish a kayak trip in BC so salt water is a possibility. But I did take it all apart and clean it plugged flushed the line more than inece with fuel after “scrubbing” the line with the cable. I would have thought any salt might be long gone. But that is good to know. Thanks!
Looks like that is my next step if the orange doesn’t go away over time as the mystery response to cleaning. I will keep this tip in my back pocket for now. Thanks!
I hadn’t u til I tried the tea test last night. Is this something I should generally do? What does that do for the stove?
Hello Brenda, Good to read, your stove is working well. Rinsing with fuel will not remove salt residues, as they are water soluble. But they will disappear over the time. When the stove is hot, they will go with the heat. That also explains, why the flame is more yellow, when hot. More heat means more salt residues will burn away. Just use it and don't worry about the yellow colour. Yellow flames resulting of to much fuel to air ratio that causes a to rich burning stove, is a different issue. As far as I can see in your video and your description (esp. no soot, etc.) that is currently not the case here.
Flushes, burns residue, seats metal, fully tests all systems. I tap the fuel line while hot to dislodge. You can see particles burn in the flame.
I see others have helped you, I'll just add that the dreaded yellow flame from too rich fuel-air mix is a lot softer yellow, akin to the yellow flame from a candle or open fire. Any other strong yellow, orange, or other funny colours are almost always of foreign chemicals in the fuel or from the burner like in this case. I've simply learned to recognise the "candleflame colour" and not to worry too much of the others. In case both rich fuel mix AND foreign chemicals are present, things get more interesting. In my experience, the funny colours then happen in the first part of the flame, and the candleflame yellow comes after that. (If its bad, the tips turn to black whisps of soot) Do others agree with this observation?
