i’d some work to do to get the stove fully functional, fettling the quicklighters and silbrazing a pinhole leak in one of the burners in THIS thread and converting the pump to a leather cup washer from the O-ring original HERE. I’ve removed the gimbal uprights for this photo (foreground). The Optimus has a very clever arrangement of an adjustable counterbalance - that chunky looking square section bar along the front underside in this shot. So depending on the weight of pots (on either or both burners) and contents and how much fuel is in the tank, quick and fine adjustment is possible to level the stove top when the brackets are configured into the gimbal movement position. I’d some fettling of the counterbalance weight to do. The substantial stainless knurled screw is my addition, the original screw in front of it. Too puny to carry the weight, the one at the other end had sheared off. I drilled and tapped to accommodate a more substantial gauge of screw. Length of the steel bar is 454mm, 27mm square section, weight 6kg. When swinging on the gimbals, the reason for the raised cup around the pump knob makes sense - holding it with one hand, pumping with the other. Time for a brew. Quicklighter in action on the other burner, one already lit. With the modification of replacing the O-ring pump piston with a proper leather cup, the enhanced efficiency of the pump makes it perfectly possible to have both quicklighters on the go while keeping the tank pressurised. Both going well ... ... but only one needed for my kettle. From the fettling post, some pics of the working components and stove deck and frame. An enjoyable project and a fine stove that’ll be getting a lot of use - on land only as yet. John
Good Morning, @presscall, John, Thanks for a very detailed post on this, for me, heretofore unfamiliar stove!! It looks like a combination of simplicity, and complexity that I'd never have figured, until after seeing this post of yours, my friend!! WOW!! As always, I'm impressed by the way your creative mind works, and your skills on sussing out even the more minor details when fettling stoves that require more than your average amount of intelligence!! WELL done, and thank you for sharing this here! Your posts like these are always much appreciated by us all, and I always wonder what you'll have up next in the que for fettling!! Enjoy this wonderful Optimus 155!! Take care, and God Bless! Everey Good Wish, Mark
Thanks Tony, Rob, Mark. @Doc Mark Well Doc, I appreciate the comments very much, but you’ve consistently set the bar high yourself. Not flattery, but fact ... with some extraordinary specimens trawled from that ‘ol Hobbit Hole of yours. A clue: a quote from a journal article: John
Dear Prescall, I tried to restore a 207b burner...but when I totally close it, still some fuel is coming out (when I bring the tank on pressure). I used all the components you can see in the photo. It seems that you know a lot about this kind of burners, what can be wrong? Kind regards, Marcel
@marcellev Hello Marcel. I don’t know if you’re aware of setting the jet pricker rack at the correct height in the burner? With the jet removed the pricker rack can be released from the control spindle pinion teeth by turning the control spindle anti-clockwise. The control spindle is then rotated clockwise to shut-off then with the pricker re-inserted (not fully, only the end will insert), the spindle is turned slowly anti-clockwise. The number of ‘clicks’ as the pricker rises then falls on the pinion teeth is counted. Three, sometimes four, is about right. The spindle is then rotated clockwise and the pricker rack descends into the burner. If the ‘clicks’ were counted incorrectly (too many) the pricker rack will be too low in the burner and itvwill prevent the burner spindle shutting off fully. Probably that? John
@presscall Wonderful fettle and even better photo journalism. Now you can walk away from your boiling kettle and not worry about burning your house down in case of an earthquake. That's a great stove with those quick lighters. Ben
Hello John, I tried the burner today...renewed a lot but still big yellow flames and smoke, could it be the wrong fuel?The former owner told me he always used any kind of lampoil. I bought one with the specifications C10-C13, no other C range. Or can I better use very clean QLIMA (used in heaters)? Kind Regards, Marcel
Being sure the jets are tightened up sufficiently is the first thing I’d check - not so much to strip the threads! Loose jets create those symptoms. A heating oil (kerosene) is ok. Preferable to lamp oil.
Sorry to bother...and second check... By the way, look what I found! Original Leaflets of the optima you restored!
Hi @marcellev . I do not know how much experience you have with kerosene fuel stoves fitted with silent burners, so forgive me if I am teaching you what you already know: The “flaring” you describe can be caused by opening the regulator too much too soon, thus flooding the burner. Follow this sequence to get good operation of the stove: 1. Pre-heat the burner with the regulator totally closed 2. Allow the pre-heat flame to totally extinguish. 3. Now open the regulator slowly. 4. You should get clouds of white paraffin vapour/air mixture exit the many holes in the outer cap. 5. Only now should you light this mixture with a match or flame applied above the outer cap. 6. After 2-3 minutes of successful burn the burner should be up to the correct operating temperature, and you can now open the regulator further until full power is achieved. Best Regards, Kerophile.
I am a little bit experienced by now...But I aprreciate your comments a lot! I did exactly what you recommend though. All of the stove is new now (except the burner itself of course and the spindle (but put a new graphite and messing ring on the spindle). Now I am gonna try to empty the tank with lampoil and will put in the one John recommend (gonna buy it today). Also, there's now half a liter in it, maybe that's not enough to get the pressure optimal. The new one I will fill totally full. Maybe that also will help. I checked all the pipes for leaks, and it seemt to be ok.
Hi @marcellev . Never fill the tank more than 3/4 full as the gas space is needed for managing the pressurisation of the system. Does any one know what was the jist of the improved filler patent Primus took out? Best Regards, Kerophile.