Wandering through the second-hand marine store on Monday, I turned a corner and came across what I thought was an Op45 with an alky burner. Very crudded up, and with only two pot-stands, but otherwise intact right down to the reserve cap, for the can't-resist price of $10. When I got it home and scraped off some of the crud, it turns out it's a Primus 100 with an early-model alky burner. So I guess I now have my first Primus. Anyway, did a general fettle (pictures once I've worked out the bugs), and fired it up. It lights just fine, and burns all right for a while, maybe a minute, but then it starts to blow out at one point in the circumference of the cap, then gradually, over the course of maybe a minute, extinguishes itself the rest of the way around until it (I think) goes into a sort of underburn: dull red glow all around the wall of the cap, low flame noise, but no glow at the center of the cap. At that point, I cannot re-light it except at extremely low throttle, and it blows itself out again immediately as soon as I try and increase the flame. All three parts of the silent cap have been de-rusted inside and out. The cleaning needle was rusted off, so after some initial problems with the burner, on BernieDawg's recommendation I just removed the remains entirely. The filter mesh, in the burner, is clean. New Kerophile HR washers are in place. NRV has been overhauled and tank pressure remains excellent throughout. Problem exists with tank about 1/3 and then 2/3 full of hardware store de-natured alcohol, the same stuff I run my Op45 on without any issues. The problem only appears once the burner has heated up --walls of the cap a fairly bright orange, top of cap dark-- and vanishes once I've let the stove cool. Has anyone experienced this? Any recommendations what I ought to try next? Thanks, Alex
Sounds like your missing the inner cap, or have the wrong inner cap. If the space brtween the inner and outer caps is too wide they do have a tendencity to under burn. Also the hotter the burnner gets, the faster it goes into underburn. Pictures please.
After I cleaned the rust on my 45 it ran pretty poor ever since too. No one knows why, even the mesh inside is in good shape. Shelf ornament. Duane
Okay, prepare yourself for the worst burner photos ever posted. First, the caps: They were all three rusted together when I got it. It lights up just fine (not that you can tell much from my photography)... Then you can see the flame pattern deteriorating, at about 5 o'clock... Camera rotated for a better angle, flame pattern deteriorating further... Going... Going... Gone. And this time it went to full-on underburn. Maybe it did before, and the lights in my shop were too bright to tell. Any thoughts? Alex
That is one problem in the red circle. You still have a leak there and most likely under the the other seal/spirit cup. A flame there is enough to ignite the fuel before it goes into the caps. Causing all kinds of problems. Jeff
I had that configeration burnner 30+ yr.ago. The inner cap is burned out. finfing one may be a problem. I used a kero inner about same size and drilled holes in top. The mixing tube (mushroom part) must slide freely. It's sort of a thermistatic control of the space above the vaporizer.
Jeff: RIGHT! I'll take a wrench to that little problem. Thanks for catching that. dspearsy2k: The inner cap is "burned out"? Can you elaborate? Aside from rust, which brushed off, it seems in pretty good condition. However, I'll make sure that mushroom cap slides easily. It strikes me as entirely plausible --seeing as how everything starts just fine, then goes bad as the cap heats up-- that the mushroom could jam in the inner cap as the metal expands. Duane: You're full of good news! I guess if things don't work out, I've come out of the deal with $10 worth of parts --and some very practical education. Thank you all --and keep the suggestions coming. Alex
Sorry, the photo of the top, of the cap looks rusted thru. If not thats good. But make sure the mixer slides easy. It only moves about an eighth of an inch total but it's dependant on hot air flow from the vaporizer chamber to lift up the mixer. That regulates the temp. in the vaporizer chamber to keep it below spontaious combustion.
Right. I can see what you thought you saw. No, the caps are in pretty good shape, but I can't say the mushroom slides easily. As soon as I've had my tea, I'll go give it another polishing and see if that changes anything. I can easily imagine the mushroom heating and expanding to where it locks up. Thanks! I had *no* idea what was going on with that system! Alex P.S. Where are you, in Puget Sound?
So on mine, I've had the caps in different configurations to see if maybe it came assembled wrong, what is the three pieces order. Outer cap, mushroom piece then the inner with all the holes? Duane
That's how mine arrived: to assemble it, set the inner cap over the jet first, then the mushroom slides down into it and covers the inner cap's air holes, and then the outer cap covers the whole mess and is held steady by two tabs that go through the burner itself. Of course, mine isn't working right either, so that assembly might be all wrong. I'm off to go give it another polish and another test burn. Alex
Mine worked a little better last time I ran it. I primed first, then opened the regulator and lit the burner, at first seemed ok, but then slowly turns to yellow flames and may go to underburn. Frustrating. I believe it worked fine a year ago when I got it, but then I had to go and sand some of the rust off. There is a barely visible pin hole in the outer cap. Interesting idea about the mushroom piece raising up to allow vapors past it. Mine was not as rusted up as your inner cap is. Duane
Got it! 1) Tightened down that burner/riser joint. 2) Gave the caps a serious polishing: spun them up on the (wood) lathe, gently took the scale off with 120 grit, finished off with #0 steel wool. Chucked up the burner and polished the cap seat with steel wool, too. Funny thing, but they fit together a lot better now... 3) And this one's from BernieDawg: swapped out the old jet with a new one I *know* to be both in good condition *and* an alkie jet. Probably should have thought of that right off, but I'm a newbie, and doubly a newbie when it comes to alkies and silent burners. Whaddaya know? Runs great! There is still occasional flame pattern deterioration, but a little percussive maintenance (i.e. a slap on the side of the tank) brings out a burst of sparks, and a return to a good flame pattern. I imagine, judging by the original condition, that there's a lot of crud that'll need to shake loose and come through. Duane: with any luck, some of that will help your Op45. Gary was pretty emphatic that the caps need to be cleaned up, and that they need to seat properly atop the burner, so I put a fair bit of effort into that. I feel like a proper doofus for not swapping out the jet right off, too. Given how crudded up or worn out jets can be, it seems swapping to a known good jet should be an early step in any diagnosis, but I didn't even think of it. Good luck with your cranky Op45! So here's the "before" photo: Here's a somewhat better flame shot: And here's an "after" photo: She'll need a bit more time on the buffing wheel to look really top notch, but it's a start. And here's an interesting comparison between my Op45 alkie, with a later generation burner, and the Pr100 with an early generation burner: Thank you all! Alex
Thanks. Mine was on one end of my shelves, easily swatted to the concrete floor if necessary. Seems my jet is pretty stuck that came with the stove, in a Sea Swing which I removed the stove from, I'll give it another go, I have a new alky jet for my 111T, not sure that will work. Duane
Sorry Alex, just got back to the computer, I'm in Chimacum. Glad to see all sorted out, looks great. Cheers, Dale
Thanks for the cheering section, folks. It's slow going, but I'm learning. Duane: Maybe try Kroil to get the jet loose? The usual penetrating oils don't seem to work on bronze/brass, but Kroil has done pretty well on some seriously locked-up bronze turnbuckles, shackles, etc. I haven't any idea whether a 111T jet will work in a 45. You'll need to ask one of the senior members about that one. Dale: I'm through Chimacum every month or so, on my way to PT. If you need anything from Poulsbo, drop me a line. Alex
