Hi, Paul, I thought I'd add a bit more to my prior comments; in particular regarding -- to the degree that a layman can -- the physics behind the differences in simmering capabilities. First, as I mentioned in my earlier post, I was comparing the simmering capabilities of the older regular Whisperlite with the newer regular Whisperlite. The size of the generator tube is not an issue between the two versions of the regular Whisperlite. Next, as you correctly point out, the Simmerlite does have a fairly thin generator tube -- but the Simmerlite just plain does not simmer. There are exceptions, but I've talked to person after person whose Simmerlite cannot be made to simmer. I also have not been able to get my own Simmerlite to simmer worth beans, and I submit to you that I'm reasonably familiar with MSR products. Based on the two points above, I think that we can rule out the idea that the diameter of the fuel tube is a major factor in simmering capability -- although I would agree with you that a fuel tube with less volume would in general result in a more responsive stove. I submit to you that the issue in this case is not responsiveness. Even with the most slowly responding stove ever, one could make infinitesimal adjustments, waiting a full minute between each adjustment, until one arrived at the "sweet spot" on the valve's dial at which simmering would occur. No such point can be found on either a new Whisperlite or a Simmerlite. I know; I've tried. I think we can therefore rule out responsiveness (or lack thereof) as a major factor in simmering capability. Well, if we rule out fuel tube diameter and responsiveness as factors in simmering, what do we have to go on? Well, we do have two versions of the same stove (the regular Whisperlite). One simmers; one does not. What's the difference? Well, first, let's take a look at a modern regular Whisperlite: Note the clearance between the top of the burner "bell" and the generator tube. Now, let's look at an original Whisperlite: Note that there is significantly less clearance between the generator and the top of the burner bell. A fluke you say? Let's look at another original: Still not convinced? Here's yet another: This is my personal Whisperlite, the one I bought in 1987. Trust me; I know it well. Clearly then, we can see that the generator tube is consistently closer to the flame in the original Whisperlite. Why might this matter? In a word: simmering. Think about it for a minute. What kind of flame do you have when you're simmering? A low one. Do you begin to see what I'm driving at here? The original Whisperlites have a generator that is much closer to the flame. In low flame conditions (i.e. when simmering), the generator on the older Whisperlites receives more heat, allowing the vaporization and burn cycle to continue. The newer Whisperlites have a generator further from the flame and do not have enough heat to continue the vaporization and burn cycle. Without testing various configurations of the generator tube, I can't be 100% sure, but based on my experience with stoves and the great importance of heat feedback in the operation of pressure stoves, I'm reasonably sure that I've hit on the correct answer. You comments, questions, and feedback would most eagerly be welcomed, HJ
Morning, HJ, I agree with you, 100%, and I think you have hit the nail on the head, when comparing older regular Whisperites, with newer ones. The older ones DO simmer better, in my experience, and in truth, I'd prefer to use one of those, any day, compared to any of the Whisperlite Internationale stoves. But, that's just me, and based on my own experiences with both stoves. The regular WPL has been more reliable than the WPLI, and the older ones simmer far better than those of newer manufacture. For what it's worth.... Take care, and God Bless! Every Good Wish, Doc
Hi, Mark, Thanks for your thoughts. Of course I can't be 100% sure, but just based on my experience and general knowledge of stoves, it sure seems like the design of the generator has to be at the root of the simmering issue for Whisperlites. Just ask any Coleman 501 owner if the design of a the generator has an impact on a stove's performance. Anyway, it feels kind of good to have (at least in my mind) solved the "mystery" of why the old Whisperlites simmer better than new ones. As I experimented with my various Whisperlites, it kept bugging me that I could observe the old ones consistently simmering better than the new ones but could not explain what I was seeing. How do you keep a stovie up late at night, eh? Oh, and I should add, that the usual "tricks" to get an MSR stove to simmer should still be employed, i.e. keeping the bottle pressure low and making sure the stove is fully heated before attempting to simmer. Also, the new MSR fuel pumps have a reputation for being difficult to simmer with, so perhaps it's best to use one of the older versions. I haven't independently verified this; perhaps that's my next project, er after I've verified that MSR Reactors are consistent in their simmering capabilities of course. Just call me "Mr. Simmer." HJ
Thanks, I have learned a lot about my stove now, and mine simmers reasonably well. I did some fettling, and tested with a coleman pump. Then it starts like a Coleman, no preheating needed! but the simmering was difficult, this may be (I'm quite sure) caused by the design of the spindle. dsk
Hi, dsk, Which pump did you use? From an Apex stove? I didn't know that a Coleman pump could connect to an MSR stove. I'm not familiar with Coleman stoves with a separate pump. Is the connector the same as on an MSR stove? Do you have any photos you can post? HJ
Sorry, I forgot the photos, the connections are not equal but I solved it by a small rubber hose between the apex pump, and the msr. The clue is the knee in the apex pump, with a tiny hole. This mixes fuel and air from the tank, and makes the start easy. Im working on a copy of the knee, just an aluminum piece with 2 holes in 90 d3g meeting each other, and a tine hole on the side, hammering the tiny hole to be even tinier, to get a resistance equal to the coleman knee. Pictures of this will come. dsk
Good Morning, DSK, Your experiment sounds very interesting, indeed! I look forward to hearing more about it, and to seeing the photos of your final results. Very cool! Best to the family, and God Bless! Every Good Wish, Doc
Yes, that sounds very interesting. And when you do this, you don't need to prime (preheat) the stove? On your next attempt, will you use an MSR pump or continue to use an Apex pump? I haven't picked up an Apex stove as yet, but perhaps this will give me the motivation to do so. Very intriguing! Please post photos. HJ
I cant let it bee, I have to try. Sometimes I end up with a long nose I got an apex stove from ebay, and the little knee with the tube going up to the air in the tank/bottle was missing. I could order a brand new pump with everything but no! I made a replacement. And the first one dident work the next one dident work and I figured out, the little hole in the knee was to big. How do you drill hole smaller if you knock on aluminum it deforms and It works! Now I have to keep on and make one more just to test, I putted it on my Chineese pump (search for "stove spare pump" on ebay) and my Chineese hose with adapted stove connector. Yes it wotks on the Apex, and the Apex runs fine on a canister too! My last test was, how it does work on the whisperlite, and yes it works, I took the D.I.Y. knee from the Coleman pump, and it fits right on the MSR pump. Then pump as described in Coleman-manual 50 strokes, open valve, and light it, less than one min. later it runs nice and blue. If you need you may pumpe more. Since my whisperlite has no buildt in cleaning needle, would rather prefere to prehat the old way, and use a filter on the pump. . The filter is a pneumatic muffler they were throwing a way at my job. dsk
Hi, dsk, I'm still not understanding how you connected the Coleman pump to the MSR stove. Can you show some photos of how the Coleman pump attaches to the MSR stove? HJ
The way I did this was rough, pull out the wire from the MSR just to touch the valve on the pump when the hose is suitable pressed on both ends. Clamp if needed. I took the chanse with clamping only in the Coleman end. (Not on picture) The knee or elbow has a particularly small hole. When getting air from the flask, it gets a little mixture of fuel too, like a simple carburator. This air fuel mix is a good substitute for the priming. By some reason what I dont really understand, the stove gets enough fuel and are not using all the air during normal operation. Coleman is the one and only doing this (as far as I know). They have done this for decades, its working well, and no one else does this. I have a vague idea about this may not work good enough on the Coleman Fyrestorms, and causeng a lot of problems there. dsk
Thank you, dsk! The little tube between the MSR stove and the Coleman pump was what I didn't understand. That was a very helpful photo. Also, the diagram that you included is very helpful. That's a very interesting idea that Coleman has, including air in the fuel mix. As you say, it's a sort of primitive carburetor. Now I understand why you can light it without priming. Very interesting. Very interesting. Priming is the #1 objection I hear from hiking compatriots regarding pressure stoves. If priming can effectively be eliminated... HJ
This system does lose pressure if used a long time but not much. The coleman does need a top up of pressure more often than the msr but you need to be running it 20 min or more to notice
A little more testing's done, and yes you are right, after a while it looses more pressure than than th MSR, or even my Optimus stoves. Still, I'm impressed, Coleman has made a good stove. dsk
Thanks for the update. This is a most interesting thread. As time progresses, I'd be very interested in hearing your thoughts on the reliability of the Coleman pump, particularly the knee. It does seem like the fuel tube on a Coleman might get snagged more often that just a plain tube. HJ
The tubes are all held together by press fit elbows I have lost the last section on mine and although easy to replace if I had been relying on it I would of been eating cold
Wouldn't it still work with out the last section of the fuel pickup tube? Wouldn't the first section of the fuel tube still be down in the fuel? You'd probably have to prime the stove, but I would think that you could get it to work. HJ
Yes it works great without the knee, and the tube up in tha air, it will even burne for a longer peride before you have to pump any more. Only one drawback, you have to preheat / prime as a regular stove. dsk
