Morning, Lads, Yesterday, I threw care to the wind, and rebuilt two of my MSR yellow pumps. I believe that these old pumps are much better than most of the later ones, which replaced them, for a variety of reasons. But, I'd never undertaken rebuilding any of them, until now. I took photos, which didn't turn out that well (didn't use a tripod ), but I'm going to post them anyway, just for grins. Here's the first "victim", all spread out, and in the process of being rebuilt. Note the broken/shattered rubber air hose (brownish in color), which almost always gets brittle and self-destructs, on these yellow pumps. Also, please note the length of clear vinyl tubing that I'm going to use to try and repair the air hose. This stuff is 1/4" OD and 1/8" ID, and can be had at any hardware store. I've already replaced the pump gasket/O-ring, fuel tube O-ring, and old style fuel control valve O-ring, with new Nitrile versions. Next, I had to pull the retaining pins for the rubber air hose, remove the bits still inside the pump body, and cut out the small brass fitting that is used as a keeper for the spring, which gets compressed during installation of the hose and fitting. Once that was done, I was ready to try and fit the bits back together, using the new vinyl hose as a replacement for the old, brittle, and broken MSR rubber air hose. The pins pull right out, with a little care, but you don't need to remove them completely. Just pry them up until they no longer protrude into the body of the pump. I used a pair of needle-nosed pliers to widen and stretch the end of the vinyl hose, which made installation of the little brass fitting a bit easier, and a very sharp awl to pierce both sides of the hose. The little holes in the sides of the tubing are used to house the retaining pins, which are pinched into place after installation of the hose. In truth, using a sharp awl is not the best way to do this, as it sort of "rips" the vinyl. Even though both pumps were repaired in this manner, and they both worked quite well, I found a better way to do it this morning. Sweet Bride has a very nice specialty punch, which made perfectly round holes in the vinyl tubing! From now on, I'll use that, instead of the awl. I'll also post photos of that "updated" procedure a little later. Here's the brass fitting, installed, and ready to be pushed into it's proper home in the pump and pinned into place. Hey, not too bad, eh?!! And, here's the completely rebuilt yellow pump, all ready for action, once again! I was so happy with this success, that I immediately rebuilt another yellow pump, which worked out just as well as the first one!! I love it, when a plan comes together!! Last, here's a photo of the proprietary jet that was used in the older MSR GK, G, and X-GK stoves, and I believe, in the even older versions of this stove. It is no longer available as a spare part, and nothing else fits these older stoves, so care of it is of utmost importance. Note also, the sintered brass surge damper, which fits perfectly into this jet. The jet also has a mesh screen installed inside it, up against which the surge damper fits. I believe that the combination of both these items, which were later eliminated from the jets which replaced this earlier type, made simmering possible! Last night, I tested my theory, after we had taken our photos honoring this stove's creator, and VOILA, the little GK stove, fitted with the newly rebuilt yellow pump, older jet, mesh screen, and surge damper, simmered very nicely, and quite reliably, indeed!! The lesson here, for those of us who have a few of the older MSR yellow pumps on hand, is DON'T get rid of them, nor trade them in, which is what MSR would prefer that you do!! Instead, take a little time and rebuild them, Friends! I'm guessing that these Old Timers have plenty of years of good service left in them, and I do believe that they are much better than the pumps with which MSR replaced them! The newest MSR pump seems like a good, robust one. However, it cannot be made to simmer. These old yellow pumps, in combination with the older jets, the mesh screens, and the sintered brass surge dampers, can simmer very nicely, indeed, if not quite as well as silent burners, nor as good as a few others!! More, and much better, photos to follow, Lads. Thanks for reading, and God Bless! Every Good Wish, Doc P.S. Whilst I'm thinking about it, does anyone recognize the little brass fitting as something that can be had fairly easily? It's quite small, maybe 1/4" in length, and tapered on both ends. Unfortunately, I did not measure the two I installed yesterday, and my third yellow pump is missing this part, completely! Rather than disassemble one of the newly rebuilt pumps, I'm just going to go down to the hardware store, and see if such a thing comes to hand. Otherwise, I'll have to make one, or jury-rig one. Ideas and suggestions as to where I might find such a brass fitting will be greatly appreciated! Thanks!
Doc, Nice job on repairing that pump. I wish I thought of repairing mine before I traded it for a less sturdy one. I tend to agree on the durability of the yellow pump. The only weakness was the tubing and check valve. It appears you have found the solution, well done. As to the brass thing, I think its a 1/8" O.D. compression fitting for plumbing.
Hey, Single Burner, Many thanks! Even a blind pig gets an acorn, now and then!! 8) I was very pleased with how it all turned out, and even more so, now that I know how to better make the pin locating holes in the vinyl tubing, with Sweet Bride's special punch. I'll head down to the hardware store and see if I can scoop up a few of those brass fittings, and thanks, very much, for the identification!! Might as well have handful in stock, "just in case"! As to your getting rid of your yellow pump, don't feel like the Lone Ranger. MSR really tries to get folks to dump the older stuff, for a bit of a credit towards the "latest, greatest" item. Unfortunately, sometimes the newer stuff is not as good as the older stuff, as in the case of the older vs newer pumps. Check out the newest MSR pump, as it looks like they might have FINALLY gotten their act together on this one. But, it doesn't simmer without a simmering plate. But, keep your eyes peeled for older yellow pumps, at swap meets and such. You never know when one might turn up for you!! Thanks, again, for your help in figuring out what that brass fitting is! Much appreciated! Take care, and God Bless! Every Good Wish, Doc
Hi Doc - great article! I still have my old yellow pump even though I have upgraded to the latest mil-spec one. I'll add an overhaul to the fettling list once the domestic projects are out of the way. That damper is nothing I've seen before. Mine is pre-shaker but maybe not really early. I let my No:9 & real early G's & GK's go.
Howdy, Ross, Thanks, very much, for the kind words! It was fun rebuilding these Old Timers, and getting them back into action once more. I will probably go back and re-do the two that I already did, this time including the special hole punch that Sweet Bride has. Today, I went down to the hardware store, and sure enough, Single Burner was absolutely right about those little brass fittings! They are, indeed, brass compression fittings for plumbing! So, add that bit of info to our knowledge of parts that MSR no longer supplies, but which we can buy, for less then 20 cents, at any hardware store!! Thanks, again, SB, for the heads-up! Much appreciated, Lad! I bought 5 of those little fittings, and tomorrow, will rebuild my last yellow pump, using the fitting you so kindly ID'ed for me!! Ross, I'll take better photos of the rebuild of this last pump, and post them here. As to the extra goodies which MSR dumped in their later pumps, I think they work very well, indeed, and wish that they hadn't been relegated to the dust bin of design, when the new pumps were created. Looking back at what Colin Fletcher, God rest his soul, had to say, he mentions that the X-GK's reputation for not simmering was really over-blown. He got his to simmer, using a "wunder-gauze" from a bunsen burner. But, I'd bet a buck that his X-GK was an older one, which had the sintered brass surge damper, and the brass mesh screen inside the jet, too!! My similar pumps help X-GK stoves to simmer much better than the same stoves with newer pumps. The "non-simmering" pumps about which I'm talking, are the grey ones, the red and grey ones, and the red and blue ones! NONE of those pumps help X-GKs to simmer, whilst the old yellow pumps, WITH the addition of the other goodies, seem to simmer fairly well. On a related, but not too important note, today, I fired up my very first X-GK, and also an X-GK Shaker Jet. Then, I took sound pressure readings from both stoves, while they were roaring away. The original stove was louder, by a bit, reading out at 88-89 db's of sound pressure. The Shaker Jet X-GK was a little more "genteel", creating only 83-84 db's of sound pressure. Not too much difference, in truth, but enough to actually hear it, and also to measure it. I plan to use the meter on my MSR Firefly, which I've always considered to be the loudest stove I've ever owned. Of course, that opinion was formed before I got hold of my Primus 744, 4-burner stove, and the Swiss two- burner, both of which I feel will be louder than the Firefly!! Anyway, it was fun taking the sound pressure readings, and I'll end up doing that on many more stoves, just for grins, and creating a list of which ones are the most quiet, and the most loud, with proper readings for each stove!! FUN!! Take care, and God Bless! Every Good Wish, Doc
Nice piece of work Mark . . . .satisfying when you can fettle up something deemed as "obsolete" by way of a perfectly sound piece of renovating. . . =D>
Great info Doc! I have one or two of those yellow pumps laying around and will now undertake a rebuild on both once I find some spare time laying around. Thanks for this thread!
Hey, Sketch, You're very welcome, my Friend! I've been consumed with working on my MSR X-GK's and yellow pumps this week, and should be spending a little more time working, but...... I can't help it!! If you want me to, I'll punch the proper holes in a couple of bits of that tubing and send it up to you. The specialty punch that Sweet Bride loaned me made short work of the task, and worked much better than the sharp awl I'd used before. I have tons of hose on hand, as we use it in our business. Let me know, and I'll send them off tomorrow, so you can have them on hand when you get time to mess with your pumps. I have one yet to complete, but have lots of fun working on the stove, instead. When I do the last pump, I'll include better photos, and especially one of that special punch, for those that might want to track one down for such a thing. Take care, and God Bless! Every Good Wish, Doc
I'd be thrilled to receive a couple of those from you! Thanks for the offer. Those hoses are broken and long gone on my yellows. Once I get one of these igloos successfully built and build a pulk or two, I want to head out for a weekend with my boys and maybe even convince the wife to go too. I'd like to use an msr xgk and just might take a yellow pump along with one of the new pumps to use in the igloo. I'm also thinking of doing a much longer trip once we get snow. I know of a lake that holds a good population of Northern Pike. I'd like to go back in there for an extended ice fishing trip - do the igloo thing - and just enjoy a few days out in the middle of nowhere. Sounds fun, doesn't it? Want to join me?
Hey, Sketch, Let me get my hat, and I'll be right up!!! Sounds like a fine adventure, that's for sure! I'll setup two hoses for you today, and send them out, either today, or tomorrow. Do you want the brass fittings installed, too? I bought enough, so if you want that done, I'll send them all ready to install. Just let me know. Got to run, but I'm already thinking of a way I can stow away on an airliner, and come to play in the snow!! Take care, and God Bless! Every Good Wish, Doc
Sure, if it's not too much trouble, I'd appreciate the brass bits too. You are too kind good sir! All such adventures are currently on the side burner till we get some snow. That lake has nothing on it except ice right now, and bare ground and a major river that I doubt is frozen over yet between me and it. But it looks like cold weather is on it's way: http://pafc.arh.noaa.gov Now we just need some snow to go with it!
Many people for many years knew the old MSRs were better, People complained the pumps were changed. Ive heard a few people say the metal parts were removed. But nothing tangible. Doc . I was just on the MSR site, They still are taking the yellow pumps in trade . And the first line on their dragonfly sales pitch is. In a world that expects liquid-fuel stoves to have one setting (hot), the DragonFly stands out. Ive never been a big fan of MSR myself. I had one and it sucked. The last few years boyscouting and watching the kids struggle to get them going in a blizzard just stick in my mind. Too much complaining about the pumps when REI had the helm too. You,ve shed some new light on the pump subject, Doc. Im thinking of trying to find me a yellow pump somewhere. I sounds like the stoves will all run better with yellow pumps. I wonder if the original owner was getting royalties on the parts design and thats why MSR dropped them when sold. To cut him off. Or it was just cost cutting in general. Or they just didnt have a clue the stoves wouldnt simmer good anymore.
Thanks for the great kick in the shorts. I just finished my rebuild. I didn't even know it was supposed to have an air tube unitl I saw the photos! Good thing I didn't toast myself.
Hey, Rigglemortis (great name, by the way!), Many thanks, Sir! It's fun ain't it, getting into stuff like that! I've got another thing, about a complete rebuild of the X-GK, and I do mean complete, coming soon. Again, it's tons of fun, and the learning never stops, here at CCS!! Take care, and God Bless! Every Good Wish, Doc P.S. I note that you are from Santa Maria. We had the first CA Stove Gathering not too far from you, last year, and we're talking about Part 2. Try to make it, when we get it all sorted out, OK?!!
I haven't seen mention of the check valve. I opened my pump and found no ball check. the spring is there though. Is it supposed to have a metal or plastic check and does anyone know what size. The o-ring in there is cracked so I replaced it with a new nitrile one.
The yellow pumps don’t have a ball, there should be a teflon disc that mates up against the O-ring. In my repair of a couple of yellow pumps HERE I punched out a brass disc to replace the teflon one, absent in both pumps. The diameter of the disc is, I recall, 6 millimetres - offering clearance in the pump body NRV bore and making a seal against the O-ring.
Save the leather pump gasket from these earlier MSR stove pumps, as the leather gaskets work at low temperatures, can only otherwise be found on the New Arctic MSR stove pumps. I am not an expert, but I am less than impressed by the durability of the new MSR pumps compared to the mid-1990's pumps!! Too much plastic!
0.5mm thick Teflon sheet is available through E bay if you want to keep it as near to factory spec'.. also found suitable brass olives the correct size.
