Coleman 425E secondary burner not enough gas

According to my 425F box the primary burner is rated at 10,700 btu and the auxiliary burner is 8000 btu. My 413F box has its primary burner at 14,600 btu and the auxiliary burner at 11,000 btu. Based on my experience I agree with the 14,600 but only with the primary burner running. The flame is pretty substantial. I've never used my 425F so I can't compare the two. I have a 414 that's rated at 17,000 total but they don't breakdown the burner output. I'm guessing it's with both burners running hence the lower total output. I saw specs for the newer version of the 424 rated at 14,000 btu.

 

For the novice users, it's important to understand that the main valve controls how many TOTAL BTUs the stove is producing. Whether it's from the main or the main AND aux. The power produced comes down to one thing and one thing only: How much fuel is passing through the gas tip at the end of the generator. When that valve is full open with only the main burner on and the stove is pumped up fully, all the BTUs the stove is capable of producing are being produced at the main burner. If you open the aux, the only change is that the total output is divided between them and unequally so, when it comes to Colemans. You won't get more total BTUs with both burners than you will with the main alone. Every BTU running on the aux is parasitically taken from the main. This is one of my few gripes with the Coleman multi-burner gasoline stoves. Other manufacturers did a much better job of evenly dividing the gas so both burners could run at the same power. Is it a big deal in use? Not often at all. Do I always have another stove handy in case I need more power? You betcha! Haha!

 

The smallest (aux) burner has ofcourse less than 50% of the total output, but my wish was to make that to more than it is, not 50%, but maybe 40%

My tests resulted in going back to the original solution because it looks like that is the best for the stove.

 

Would be interesting to know why Coleman did it that way. Lots of people (me included) think there is something wrong when that secondary burner is such low power, but that is just the way it's built.

 

I always used it as a lesser powered burner. I see nothing wrong with it the way it is designed.
Otherwise, get a 426 or 413.

 

First off, 413s and 426s suffer the same design flaw. Can you work around it? Sure, usually. Should you have to? Other manufacturers said we shouldn't. And they did a better job on this.
If you have one stove that allows both burners to run very close to the same temp and one that does not, you don't consider that a design flaw in the less capable unit?
C'mon man!
Even Marilyn Monroe had a mole on her face. She was still a beautiful woman. Right?
Sure, if we look at the moles on the other brands, the Colemans come out on top the majority of the time. Overall, I consider Coleman's design to be superior. Burner power equality is not one of them.
Coleman's pump, with check valve and air passage NOT sitting immersed in fuel, with positive stop and the little hole to let you seat the pump plunger any time, and the instant lighting system's fuel/air tube make the Coleman superior overall.
We all see the mole, some of us simply acknowledge that it's there.

Have a Merry Christmas and all the best to you and yours!

 

It's been a long time, but I think the old cast iron burners were much better in this arena. Gonna have to pull out the old 417B and refresh my memory. With fair certainty, I can state that lowering production costs and profitability were likely the culprit.

Wichita Kansas, early 1945-ish: I can hear it in the board room after the new stamped steel burner prototype test. "Can we fix that?" "Sure." "How much will it cost?"..... "Oh! That much?" "Soft murmurs around the table." It was at this moment, the cast iron burners fate was sealed.

Edit: I just read first stamped steel burner assembly was a Coleman Canada "innovation". That's ok. The 550B alone made up for this SNAFU.

 

It should be evident in use to the casual observer that the auxiliary burner is just that, a 2nd burner or “back burner” intended to run low & keep coffee or food warm & ready to serve while main food preparation continues on the large burner. Are you smarter than a Coleman engineer? Maybe, but I’m sure they did it this way for a reason.

It’s plenty hot enough to fry bacon, what more do you need?

 

I really don't understand how you can continue to argue that less capability is better. Strange times we live in.

I want to be clear that I am a HUGE fan of Coleman stoves. This is a focused critique on a single element: Burner power disparity on multi-burner, gasoline stoves. NOTHING else. I believe just about every other operational part of Coleman's engineering and design are superior. Wind screen retainers on earlier models was another head shaker, but not a big deal and not the focus here.

Anyone with any historical knowledge or even a reasonable theory or excuse other than the one I suggest are welcomed and encouraged to chime in, as always.

The casual observer probably has no idea that some competing companies didn't force this limitation on their customers. Customers who may, in fact, WANT a griddle that's got even heat on both sides. Or who needs to cook more than one pan at the same heat level.

While I am certainly not smarter than the Coleman engineers, it would appear to the casual observer that their competitors burner engineers WERE. But I am NOT a casual observer. As I suggested above, I believe it's more likely that it was not the engineers, but the accountants who simply made a business decision for us. It's pretty obvious to the casual observer who's used Coleman stoves and the competitors models of the day that Coleman falls short of the others burner designs.

Is it a fatal flaw that can't be overcome by making some culinary sacrifices? Of course not. My point is, OTHER manufacturers produced stoves that didn't force those few sacrifices on us.

But, I would like to hear your take on the possible "reasons" they may have had for including a capability limitation that didn't exist in competing models as a feature vs a flaw. I don't want to straw man you here, so don't be shy.

Hope you had a great holiday season and here's to a great 2026.

Mike

 

Coleman didn't "force" consumers to buy/use their stoves, it was the consumer's choice. And an interesting choice by Coleman. Some of their older stove both burners are more or less the same output. The Mystery......we will never know

 

I never questioned it. It just is.

 

Me? I didn’t say it is “better”, that is subjective. It was a design decision, that is different. Whether or not that is “better” depends on individual preferences.

As I’ve mentioned I wish Coleman would have produced a single burner suitcase stove and deleted the 2nd burner altogether. There’s a guy on here who has made them, and they are pretty spiffy. I think they would have been “better” for some applications.

 

Magicwrench and Fettler, those ARE fair points to a degree. Brand loyalty for Coleman was very strong, an as I mentioned a couple of times, my gripe is ONLY about the original posters problem: burner power disparity. I, and obviously most stove buyers, would've still chosen the Coleman because, IMO, it's just a better overall product. The instant lighting design was the best I've ever used and still is. The pump/check valve? None better. Yes, I know, better is subjective. But it would be difficult to argue those points to a jury of knowledgeable stovies. haha! This, to me, is just the wart on the otherwise beautiful princesses nose that could have, and should have been removed. It's a bit surprising to me that the competitors in this market didn't immediately jump on their competitors better ideas as soon as patents ran out. I'm OBVIOUSLY not a patent expert.......soooo yeah.

Fettler, I have seen that neat stove chop. Well executed. I've been telling myself to make something similar and got the easy part done. I mounted a 457 HGP burner in a 413 case. Even incorporated an adjustable air choke to optimize the fuel air mixture at different heat levels. It runs VERY well. I just haven't chopped the case yet. Which IS of course, the hard part.

Hope all are having, and will continue to have a safe and happy 2026.