Need help with an AGM KampKook LCS-41 rebuild

In the last couple of weeks I have undertaken the task of dusting off and refurbishing all of my Grandfather’s old camping/hunting equipment. The gas lantern and stove he used were both AGM units, the lantern being the classic red KampLite inverted donut model, and the stove being a 2 burner KampKook model LCS-41. I used both of these extensively in my youth from 1982 until around 1985, when I got tired of the constant tinkering they required, and bought new Colemans to replace them. My being 16 years old at the time, I of course put both units on a shelf without even remotely considering emptying the fuel tanks. So cut to 25 years later, and what I found left in the stove tank is about 12 ounces of Amoco premium unleaded gas and a half ounce of sediment. I never ran leaded gas in the stove, but did use what I felt was the cleanest auto gas I could get at the time. Obviously the choice between paying 75 cents a gallon for super-unleaded or $3.00 a gallon for Coleman fuel is not a tough decision for a kid on an allowance. Just to clarify: once I get everything back into shape, I intend to use Coleman fuel in it from now on.

The first thing I did was to get online and look for some info on how to disassemble the tank and valve assembly. I didn’t even bother with trying to see if the stove would run because I wanted to clean the tank of all sediment and rust first, and it was barely running when I put it up 25 years ago anyway. I’ve found lots of invaluable information on rebuilding and tweaking stoves both here and on some other sites, and now have a pretty thorough understanding of how everything works and goes together. God bless the Internet. I’ve been camping for almost 30 years, yet never knew about preheating a temperamental generator until a week ago. If I were trying to rebuild an old Coleman stove, I would be set, for there is hardly an aspect of Coleman that is not documented, discussed, and pictured online. However, the subtle differences of the AGM have left me with some questions I hope can be answered by some of the more experienced AGM owners here on the forum.

I have been taking pictures during the process of disassembly and promise to post them soon. I have compiled a list of questions, which I will hit upon later, but for right now, my primary concern is what to do with the generator tube. It is the type with the 5/8 by 3 inch cylinder sitting on top of the primary tube. I read in another post here that the purpose of this extra cylinder was to enable it to burn the leaded gas which is mentioned in addition to regular white gas on the lid’s decal. I understand how the cylinder could act as a further heat sink for the generator, but someone also mentioned a screening material in the cylinder which served to catch something (lead possibly?). All of the fuel is not diverted into the cylinder; half of it just passes right on thru the lower tube. What about this fuel which doesn’t get filtered? Does this extra cylinder make the generator impossible to clean, replacement being the only option, and I’m 40 years too late for replacement parts? I have taken the generator tube out of the valve assembly. The cleaning needle, of course, stayed with the fuel valve. The gas tip also unscrewed, leaving me with just the tube and what I assume is a coil inside it. I soaked it in carb cleaner, after which I can hear the coil rattling inside when it is shaken. When I look down the end that the coil should come out of, I see something a few inches down inside resembling a washer with a 1/8 inch hole in the middle which is blocking access to the coil. Will this washer come out? Is its purpose to partially restrict the flow of fuel and enable the backwash to divert into the cylinder? Do I even need to get the coil out or can I do an adequate job by soaking and rinsing with carb cleaner? What are the benefits of heating it to burn away carbon deposits, and what is the best procedure for doing this?

Thanks for any help, and I promise not to be so long winded with my follow-up questions.

 

For now, I'll attach this image of someone else's identical LCS-41 for clarification of the type of generator mine has.

 

Welcome to the forum!

I'm not the guy to answer your questions, as I don't have a KampKook, and someone much more knowledgeable than I will be along soon.

I will say that you seem to be approaching this the right way (i.e. slowly and deliberately). Also, you're right that even a stove that accommodates auto gas will run better on Coleman fuel.

I have done generator refurbishing on Coleman stoves, and I would not try to burn away the carbon in the generator if the treatment you've done has freed up the mechanism.

However, as I said, someone with actual KampKook experience will be along soon.
....Arch

 

Right you are, "40 years too late for replacement."

short of cutting the cylinder open with a hack saw and then welding it shut there is no way to "service" these generators. I could do it but you may not have the skills or the desire to attempt such.

That said if you really want to have this done send me a PM (priviate message) and i will return with my shipping address. You will have the generator back in about a week.

As i see it you have now done more to service a kampkook generator then anyone i know.

WELL DONE, and welcome aboard the ship of stovies.

LANCE

 

Thanks to ArchMc and Lance for the warm welcome. I knew Lance had mentioned in another post that he had 2 KampKooks, so I was hoping that he would chime in with some advice. I may very well take you up on your offer to work on the generator for me if it turns out to be necessary to do so; thank you for offering. I have some questions about what exactly is the benefit/end result of brushing all carbon deposits out of a generator, but thought I would research a little more before asking "stupid questions".

I finally got some pictures edited, so thought I would put those up for now. When I get the stove put back together I'll be sure and contribute some nice pics to the Stove Gallery.


The happy couple after 50 something years together. Note the mouse nest behind the manifold.


Decal says it "Burns Regular or Leaded Gasoline"
Me saying to self in 1982, "but I thought Leaded gasoline was Regular?"


Varnished fuel ended up lots of places.


I vaguely remember at some time dropping the tank and bending the generator tube.


Here's what we're down to with the generator so far.
down inside the generator tube.
The rod in the foreground is a fiber optic flashlight wand, not part of the generator.[/b]

The barrier is concave, and is in place right after the tubing leading to the large filter cylinder. The orifice in it is just a little larger than 1/16". The tubing leading to the cylinder is 1/8" OD, so I assume its ID would also be around 1/16". Seems as if the generator was designed to send half of the fuel thru the filter and the other half straight down the tube unfiltered. I have considered just expanding the barrier orifice to 1/8" and not worrying about whether any fuel gets thru the filter or not. I, however, don't know whether any junk that is currently trapped in the filter would affect operation in any way: for instance, moving forward and clogging the gas tip. I guess I could always just cut the filter off and braze over the holes since I'll be using only Coleman fuel in it, but I think the odd looking generator adds to the whole stove.

I'll be back with more questions later.

 

In the late forties and fifties regular did not have lead in it only premium did. Lead was not added to automotive gas till after world war two. Mike...

 

A few years later, someone did explain to me that lead didn't used to be added to any gasoline. I had forgotten, however, that premium was once leaded until you mentioned it. I remember reading in an old car owner's manual where it recommended using only premium leaded gasoline. It seems that it was the manual for a 1959 Pontiac Catalina Safari Wagon with a 389 motor that we once had (well, I actually still have it; it's rusting away in one of the sheds of our barn). Was premium leaded still available in 1959, or am I remembering the wrong owner's manual?

 

Leaded gas was available in all grades till the late 80's and longer in some areas. You are right gas originally had no lead in it. Leaded gas was devolved by Shell oil under the direction of Jimmy Doolittle for use in high performance military and racing aircraft. Some ultra expensive high performance supercharged cars in the 30's such as Duesenbergs used leaded fuel, but their owners had to go to designated airports to buy it. Mike...

 

Interesting. i have never seen this combination for a generator for a kampkook before. All of mine are straight through with a larger diameter Swell directly over theburner to vapourize the fuel. Hummmph i'm at a loss on this one. Still if you need the work done to it i'll giv'r a go and git'er-done for you.

lance

 

Gentlemen, if I may add something. Lance is correct in stating that this style generator is not serviceable. It is, for all intents and purposes, a sealed unit. I imagine one could cut it open, clean it out, service the screening material and re-seal it. But care should be taken in that if it is sealed shut that the material used will not melt under the flame of the burner.

The purpose of the cylinder on top of the generator is indeed, a filtering canister. These were used only on the LCS series of KampKook stoves and on some later Thermos stoves. Generators do not interchange between KampKook and Thermos stoves, according to my Thermos parts book. The KampKook used two different leaded gas generators. One for the compact LCS stoves(LCS 2,6,21,21A,22,2522 & 2522A with part # S-265)and the larger LCS stoves(LCS 4, 41, 41A, 42, 61 & 61A with part #S-5191).

The white gas models(WCS) used a straight generator, like Lance's and there were two lengths also. Compact WCS #1,5,11,11A & 12 used gen.#428-138 and the larger WCS #'s 3,31,31A & 51 used gen.# S-5192. That gen does come up on eBay once in a great moon and interchanges directly with your LCS-41. Again, later Thermos stove gens won't work. I don't know why but if Thermos listed it differently from their stoves, they had a reason.

Myself, I would somehow bypass the filter canister, seal off the small tubes and drill out the orifice to be the same diameter of the gen tube, and re-use it for the white gas, like you want to do. The gen needle shafts are the same between the leaded and white gas models, as are the valve stem and valve body.

Flivver was correct in stating that lead was added to all automotive gasolines, I believe after WWII. Only difference between the 3 grades, other than possibly more additives was the octane rating, premium being the highest with at least 100. Sunoco offered 104 octane. Regular usually had at least 92, ethyl around 95-97.

White gas was still offered up until about the 70s, at least where I lived. And that only at one of those cut-rate stations that had a separate pump away from the rest of the gas pumps, kind of like some stations have a either/or a propane tank and a kerosene pump off to one side of the station.

 

Enlarging the orifice to the same 1/4" diameter as that of the gen tube would provide the coil with 2 inches of space to travel back and forth in. That could potentially leave the final 2 inches of the gen which sit over the burner without the extra heat transfer of the coil if it happened to be shifted toward the back side of the tube at the time. Could that be a problem? Are there any Coleman gens with 1/4" ID that I could use the coil from, trimming it to the exact length of my tube; I'm assuming the only thing important is that the coil be as close of a fit to the tube walls as my original for maximum heat transfer? My gen tube is 8 3/8" long from back to tip.

What if I don't use a coil at all, and instead, place a number of rods of brass or other suitable material all around the gen needle as was done by the manufacturer of another stove I saw here on the forum?

Or what if I just leave well enough alone and see how the gen works when I put everything back together? I know the main tube is not blocked; can't say for sure about the filter. I could enlarge the "barrier" orifice to 3/16" or so and the coil would still stay in place, and flow thru the main tube would be greater than that which the gen originally had (one 3/16" orifice vs. the two 1/16" orifices fuel ran thru before). The gen tube just wouldn't be sqeaky clean inside and would still have some carbon on the coil.

How does carbon negatively affect a gen's operation other than blockage? How does it cause a yellow flame in the stove; does it prevent efficient heat transfer, and therefore, cause the gen to inadequately vaporize fuel? Can carbon in the gen cause pre-ignition inside the tube? Assuming I have plenty of fuel flow thru my gen once I put it back together, what other problems might the carbon remaining inside cause?

Thank you coleman413c for the gen part #s. I will keep a lookout for the white gas gen to come up on eBay in the future. I would like to have one on hand were my gen to ever become completely unserviceable.

 

Now a question about the rust in my tank. I saw a suggestion to use BBs to roll around inside the tank to break free rust and scale. What I've not seen discussed is how bad is bad. The inside of my tank ranges from about 70% looking like what you see in the first picture, 25% looking like the dark rust in the lower corner of the first picture, and 5% having the large chunks of scale that you see in the second picture. I was thinking of using something like lead pellets to shake around inside, as they would be more abrasive than BBs, and possibly better remove rust and scale. Would they, however, do more harm to the smooth surface that I do have than any benefit might be worth?

 

While I can't be of much technical help, I can try to supply moral support.....you can do it man! With Lance offerin' a hand and Coleman413c's encyclopedic knowledge, you're way ahead of the game. I've two AGM KamKooks and they have odd generators also....here's for some inspiration for you......and hopes that you get this girl goin again! There just aren't enough left!!

https://classiccampstoves.com/threads/10671

https://classiccampstoves.com/threads/10675

 

Hello VooDuuChild
I indeed found your 2 stoves in the gallery not long after I started looking around on here. The document with the entire bronze (I won't call it pink) colored line-up on it was very helpful in figuring out what model # I had (41 vs. 42, WCS vs. LCS, that sort of thing). I later found the numbers on mine, but it took some cleaning before I saw them. Now if I could just find someone with an owner's manual for my exact model, that would be fun to have a copy of. The documentation posted here is invaluable; already I've learned numerous lighting tips on my stove from looking at a Ted Williams manual, and some of the old Prentiss Wabers parts diagrams helped me identify all the parts in my generator, valve, and pump assemblies before I disassembled them.

Your LCS-21 seems to have the same gen filter that Lance was describing on his. I wonder if the main gen tube just has numerous holes bored in it to allow the gas to flow in and out of the filter?

Algentry1's stove has an even different gen filter than either of ours, with 2 tubes on one end of the filter.

 

It would be better if you used small machine screws and nuts less than 1/2 inch in length. The reasoning for this is if you use steel screws and nuts you may then lift them from the tank with a small magnete. And they will clean better than lead pellets.

You asked about the buildup of carbon in the generator in an earlier posting. Aside from reducing flow the carbon has an insulating effect, and does infact, reduce the efficency of your stove. This applies to all stove and all carbon buildup.

There are some who balieve a bit of carbon on the bottom of their pots decreases boil times. This is only true for pots which are a shinny metal. Dull metal or copper bottom pans infact do not benifit from this carbon.

lance

 

Lance is correct in suggesting using small screws and nuts in cleaning out your fuel tank. They will not only do a better job of loosening the rust and scale but are much easier to extract with a magnet. Would be also nice if you had access to a paint can shaker. Works wonders in working that hardware inside to clean.

As for your gen questions again, wouldn't hurt to try and clean the gen as it is and trying it to see how well it would function before resorting to all that work and trying to remove the filter canister and drilling out that orifice.

I checked a couple of gens in my garage and found that the Coleman 425 gen might help you out a bit. I measured the gen tube and coil and it is real close to what you need.

The gen tube measures 8 3/4" long with gas tip, 8 7/16" long without tip. Tube has an O.D. of 5/16". I forgot to measure the I.D. BUT measuring the gen coil, that measures 8 1/4" long, 3/16" OD at least 1/16" to not quite 1/8" ID. Safe assumption that the ID of the gen tube is 1/4". And the beauty of 425 generators is that they are plentiful and reasonably priced. They are not a high demand stove gen. They come up on eBay all of the time. And should you be fortunate in coming across, say a 30s to 40s vintage Coleman Hot Plate or camp stove, odds are that it will use the very same generator. With few exceptions, most of them did. Sorry I digressed on that!

As for the carbon build-up affecting the operation of the generator, depends on the severity of the build-up itself. If light, very little effect but if it is heavy, yes, it will affect proper vaporization of the liquid fuel. Carbon can act as a sort of insulator and prevent the burner heat from vaporizing the fuel properly. So in essence, the stove would burn rich for a while longer than is the norm but the generator will eventually get hot enough insie to vaporize properly.

As for your yellow flame, either a worn out gas tip on the generator, worn gen shaft needle or some sort of air blockage in your burner chamber/manifolding.

All it takes is a small spider web, at least, to make a stove burn yellow meaning rich. It's amazing what insects find attractive inside the chambers/manifolding. You name it, I've found it inside some old stoves. Dead insects, webs, nests from mud daubers,etc.

The design of the filter canister on top of the gen tube was such that most, if not all of the fuel was designed to go through that filter then back into the tube, in a circular pattern, then on to the stove to be burned. How, exactly, it was supposed to do that, I don't know but that's what the info I've found has mentioned. I have seen an artist's rendition on how it does it to impress potential customers, I guess, but no technical drawing of it as to how they accomplish it.

 

Lance
Thank you; great idea with the nuts and bolts. Can't believe I didn't think of that, as I buy grade #2 hardware by the pound at Tractor Supply Company all the time. I asked everyone at dinner a few nights ago for ideas and the only suggestion I got was Grape-Nuts cereal. I doubt you shop at TSC, as I remember being in the Quad Cities on a Sunday several years ago needing a fuel pump for a portable diesel fuel tank, and couldn't believe there was no TSC around. I had to drive about 50 miles south just to find one, then come back and work in the dark in the middle of February.

coleman413c
My gen tube O.D. is also 5/16" and the I.D. is actually about 1.5/64" less than 1/4" on my dial caliper (so an even better fit for the 3/16" coil of the 425 gen). I was thinking: would it be foolish for me to wonder if the 425 gen tube is the same thread pitch as that of my AGM, and if the 425 gen's cleaning needle might be the same length and thread size as that of my AGM, and if the 425 gas tip might be the same O.D. as the AGM's? You see where I'm heading?

Indeed, when I first started disassembling the stove, I discovered that dirt daubers had signed a 25 year lease and moved into the u-tube of my manifold. I poked and brushed the poor mummified spiders out, then used aluminum foil to adapt the gas tip of a Coleman 428 tank down to the smaller diameter orifice of the KampKook's manifold. Even after 15 minutes of running, I never could get a completely strong blue flame; but many other variables could have been involved at that point (gas tip instead of the gen tube was sitting directly over the flame, burner caps and rings were already unscrewed and just sitting loosely in place, etc.)

My preference is definately to use the generator that came with my stove, but if things don't work out, it's nice to know that I have options. Is the current Coleman #412-5621 generator the same as the one you are talking about?

 

You are correct in asking if the 412-5621 stove generator was the one I was referring to.

And I know exactly where you are leading to regardng trying to use the Coleman gen as a replacement for your Kampkook, or a combination of parts. It definitely wouldn't hurt to try and see if it would work. I'm curious myself. I don't know if the thread pitch is the same between gen tubes. I know the Kampkook one has fewer threads than the Coleman one.

 

I sometimes use BB's in my stoves but i'm using the zinc coated steel ones sold by Crossman.

I like the sound they make as they rattle about in my tank when i'm hiking after bear. They make an equally disturbing sound in the tank of some jerks car.

lance

 

On to another issue. I recall back when I used the stove regularly that it required re-pumping every 10-15 minutes to keep the pressure up. Upon inspection of the pump plunger, it’s now obvious that the valve tip was never seating properly in the back of the check valve assembly, having been ground off by repeatedly being slammed into the threads that come before the valve seat. The first question that came to mind was how does this not happen to any pump plunger that has a valve at the end, as opposed to those which ride on an air stem like Colemans do. Is this deformed tip a common problem?

With the pump plunger obviously incapable of sealing off the tank, I can only hope to get a good seal out of the check valve by cleaning it as much as possible. Is it possible for the check valve to provide a tight enough seal to negate the need for sealing it off with the pump plunger? Or was the 10-15 minutes that I used to get between re-pumping as much as I can hope for? I attempted to disassemble the check valve from the end of the pump tube, but was unable to get it to budge. Any ideas here; I’m surprised it won’t move, as this is the only part in the entire disassembly of the stove that hasn’t easily come apart. Is there even any reason to take it apart, or can I do just as well by soaking the entire assembly in carb cleaner?

I may at some point break down and buy a KampKook off eBay to salvage an easier to disassemble white gas generator and a better looking pump plunger assembly. Of course there’s always the risk that I’ll get another one with a smashed tip. As I keep saying, however, I really prefer to keep everything original.

Thanks for any help.

The good pump plunger for comparison purposes is out of my AGM KampLite lantern.
The pump leather on the right was the best I was capable of making when I was 13 years old; new one from Sefa will be on the way soon.


I assume the portion with the wrench flats unthreads from the tube, but what’s up with the recessed ring near the end of the tube?