Dear Ian, and Stove Mates, In response to your question about Optimus restrictors, I decided to check out the ones I have on hand. I knew that Optimus had changed their restrictor design over the years, and their instructions are confusing, at best, and do not really tell us all we need to know about using such an item. So, for what it's worth, here's what I found. I have three different types of restrictors, all made by Optimus. I'll call them restrictors 'A', 'B', and 'C'. The first two restrictors, A & B, are made of chrome-plated brass, while type C is made of plain brass tubing. A - Made of chrome-plated brass, it has a flange at one end, used as a 'stop', and two holes at the other end. Length = 40.04 mm OD = 12.96 mm. ID = 12 mm. Holes = Two holes at the end opposite the flange, holes opposing one another. The bottom edge of each hole is 1.58 mm from the end of the tube, and their diameter is 4.44 mm. This is the original Optimus restrictor # 5163, and it came as standard equipment, for use with Meths, in the original 111T stoves, and also the 199 stoves. Then, Optimus changed the design of their Meths restrictor, and labeled the original #5163 as for use with Petrol. Their 'new' Meths restrictor became #5213. That is the restrictor I am calling 'B'. B - made of chrome-plated brass, has NO flange at all, and has two different sets of holes, one set on either end. Length = 39 mm. OD = 12.96 mm. ID = 12 mm. Holes = One end has two holes, opposing one another. These two holes start 2.22 mm from the bottom edge of the tube. Their diameter is 3.46 mm. The other end has THREE holes, setup in a triangular fashion, evenly spaced from one another. These holes start 2.22 mm from the edge of the tube. Their diameter is larger than the holes on the other end, at 3.46 mm. In the Optimus diagrams, it would appear that the end with the three holes is placed into the burner tube first, and the end with the two holes would be upper most. Now, comes the interesting part, as if this whole thing was not interesting enough!!! In one of my 199 stoves, the one I keep setup for use with Meths, I found a THIRD type of Meths restrictor!!! C - This restrictor is made of unplated, plain brass tubing. It has NO flange at all, AND, it has four holes in each end, each hole opposing another!!!! Here's the drill on this one: Length = 36.85 mm. OD = 13.13 mm. ID = 12.15 mm. Holes - Each end has four holes, one hole opposing another. Each of the holes starts 3.29 mm from the edge of the tube, and the diameter for all eight holes is 4.36 mm. Are you all totally confused yet?? Hell, I am!! : ] It's no wonder that some of us like using Meths in our 111T and 199 stoves, and others have no luck at all with it! Not only do we all use different types of Meths, but there are at least three different Meths restrictors from Optimus floating around out there, and maybe MORE!! But, the good news is this: In the 199 that I love using with Meths, restrictor 'C' has been installed for a good long time. This restrictor would seem to be the easiest to make for yourself. The opposing holes, and the symmetrical design should be easy to cobble up, and this restrictor seems to work VERY well with my 199 and 111T stoves. Note that I use the proper alcohol nipple, AND, the restrictor, when I burn Meths in my 199s and 111T stoves. Additionally, I have used the other two types of restrictors, and thought they worked pretty well. But, upon experimentation, I believe that restrictor type 'C' is the best of the lot. Again, this one would be very easy to make. Ian, let me know if you still want me to send the type 'A' restrictor that I have on hand. It's yours, if you want it. But, if you'd rather wait, and see if making a type 'C' would work for you, and you don't need the type 'A', that's OK, too. Just let me know, and I am happy to do it, either way. I hope this information will prove helpful to those that wish to make best use of burning Meths in their 111T and 199 stoves. I have had wonderful luck doing do, and hope you do, too. Take care, and God Bless! Every Good Wish, Doc Mark
Mark, Thank you for all that info - I'll certainly be having a go at making a restrictor of some sort as soon as I find some suitable tube. One more question; with the 'c' restrictor do the upper holes coincide with the 4 holes in the top of the burner tube? Should they? Does it matter? Hopefully I will find a bit of spare time to make one up before Friday but I've any number of more pressing jobs still to do. We'll see.
Greetings, Ian, You are very welcome, and I hope that the info proves of value. I did find out one more thing that I wanted to pass along. For the life of me, I couldn't remember WHERE I got the type C restrictor. Then, , it dawned on me! It came from an Homestrand Mariner Alcohol stove!! It's not from Optimus at all, but rather from SVEA! SVEA made all the burner parts that Homestrand used in their Mariner stoves, and as this particular model was setup to burn Meths, exclusively, it's no wonder that the type C restrictor works best, even in the Optimus silent burners!! The Homestrand part is #15393. I have three of the Homestrand stoves, one of which I used for parts, and all of them have this type of restrictor. In the mean time, however, do you want to have the type A restrictor, just for grins? It _was_ standard Optimus equipment for the 111T stoves, until replaced by what I call the type B restrictor. Just say the word, and I'll post it to you, straight away. It's an extra that I got with a bag of parts, many years ago. I can post it today, if you want it. Again, have a fantastic time this coming weekend!! Damn! I sure wish I was going to be there with you Lads!! Take care, and God Bless! Every Good Wish, Doc Mark
Mark, might be as well if you hang on to the 'A' restr. for now. If the 'C' works best I'll try making one of those first and take it from there, But thank you for the offer anyway; Im very grateful.
Hi, Ian, and All, This afternoon, Oops wrote me a PM with an interesting suggestion. He's trying to make his own restrictor, and tried using an empty cartridge case, with the head cut off of it. I never thought about making a restrictor out of a cartridge case, but that's not a bad idea! I just went downstairs and checked out a few different rifle and pistol cases, and it looks to me like the one that would work the best is a case from a .45-70 rifle. I will have to find an empty .45-70 case and see if it can be made to work as a proper restrictor. IF this works, I can supply some empty .45-70 cases to any that might wish to give this a try. I'll try to get to it next week, and see how it turns out. Will report back with the results. Thanks, Oops, for the idea!! 8) Ian, I will save the type A restrictor, and should you need it, after trying to make your own, I will send it along to you. If the cartridge case idea works, I will send you a few empty .45-70 cases to play with, too. OH, and I forgot to answer one question you asked: No the top holes do not line up with the four holes that are in the burner tube. When I first saw them, I thought, as did you, that they would probably line up. But, in actuality, the upper holes in the restrictor are slightly above the ones in the burner tube. I have no idea why, but it all works perfectly, in practice, so I guess it doesn't matter. Take care, and God Bless! Every Good Wish, Doc Mark
This in combiation with bad meths, may be a reason for my dissatisfaction with this. I still belive theese burners ar made for kero, and all other fuels is only an extra possibility, and not optimal (The base in the brand OPTIMUS) dsk
