Hi everyone. I recently bought an Anchor 950. It pumped and held pressure for a while, but the preheater was not working. It seemed to work fine on a meths startup and boy, was it bright with a Butterfly #41 mantle fittted. I stripped the preheater and soaked it in Cellulose thinner for a cople of days and re-assembled. Result! the preheater works, however it now loses pressure even after the pre-heater is turned off. I dug the little rubber valve cover pip out of the starter lever as it was heavily dished in the centre, and reversed it which seemed to help, but now the main fuel shut-off valve leaks constantly from the jet nipple, even though the pricker is well up in the jet. I now cannot get enough pressure to operate the pre-heater without fuel leaking from the main jet. It may have been stored for years as it came from e-bay. Eventually I managed to remove the control assembly which was very tight and the lead washer which was dished and distorted using a small blowtorch. I was able to remove the control screw and get the control rod out of the vapouriser/control cock. At the base, the foot valve has what looks like a very small rubber o-ring type washer in a brass tube with brass showing in the centre. Does anyone know if this should be a solid rubber piece or should it have a hole in the centre? It is certainly disintegrating. Can either the seal or the foot valve still be purchased? Any help would be appreciated.
It is not a solid rubber piece, the seal has a hole in the centre. I don't remember anyone selling replacements. Someone else may know. I made one by drilling a hole (for the centre) in a sheet of viton and a punch to cut the outer diameter. It took a couple of attempts to get one usable. Can't remember the dimensions now. A bit of a buggar to get in the brass holder as the central pin is swaged.
Correct. The valve is basically the same as the one in the pump tube i.e. a springloaded rubber pip, the difference being the small piece of brass which gives the rod something to push on without distorting the rubber washer. No need to buy a complete new valve, just get the pip #193. Seals such as #229, #90 and other spares are available from base-camp Petromax Spares Price List After you've fixed and re-assembled your lantern, don't forget to check the air gap between the jet and the bottom of the mixing tube.
Hi again. Replaced all the seals and the rubber valves. It works again, but…. I replaced the mantle yesterday as it was damaged, and noticed that the Mixer (above the ceramic holder) was loose. I tightened it and re-assembled it all. The light was poor with a large corona around the mantle which was becoming sooty and giving a poor red light. The J pipe was noticeably glowing red. Today I investigated a bit more and realised that the mixture screw was no longer visible through the chrome cap. It seems that the j pipe had dropped when I tightened the mixer. I have read that the optimum gap J pipe to nipple top is 14.2 - 15mm. The maximum I can get is about 13.7mm. Maybe this is why the mixer had been left loose. Do I shorten the J pipe to get 14.5 mm or just leave it? After about 2hours running today most of the black has gone from the mantle. The air adjustment screw is badly chewed up and will not move but the paddle is vertical in the tube and the light seems bright. Any advice would be appreciated.
That rubber piece certainly sounds like it has reached the end of its life, especially if the lantern may have been sitting for years. I would not try to judge the original shape from what is left of it now. Once those old seals start hardening and breaking down they can look completely different from how they were made. If the valve is no longer shutting the fuel off properly, I would replace the seal before running the lantern again rather than trying to reshape the old one. I would also check whether Anchor 950 parts cross over with any of the Petromax style lanterns. A lot of these designs share similar components, although I would still compare dimensions carefully before ordering anything. If you can post a clear photo of the foot valve taken apart, including the brass carrier and whatever remains of the rubber, someone who has rebuilt one of these before may recognize exactly what belongs there. Given that fuel is reaching the jet when the control should be closed, I would definitely get that valve sealing properly before doing any more testing with fuel.
Thanks @Valkyrie. I have done all the seals now. Lead joints, gland packing, base valve assembly (same as Petromax) and preheater seal, (all from Base camp UK) and followed Loe's suggestion by removing about 5mm from the jet (nipple) end of the J tube. It is much happier and no longer sooting the mantle up. My manometer lens had frosted, maybe got a dose of cellulose thinner on it accidentally. Base camp supplied me with a Petromax version, but the rim was too thick to allow the fixing screw to fit. A hour or so with fine carbide paper let me remove most of the rear raised lip and it now fits. Almost there now; I have a gap of 14.6mm tube to jet. My only remaining problem now is the mixture screw which had tightened and the slot is badly chewed. Fortunately the paddle is vertical so I may just leave it alone as it kept on moving anyway. I could persevere and drill it out then make a new paddle but general opinion seems to suggest that it needs to be either vertical or removed altogether and the hole blanked off with a very short M4 screw or silver soldered up. Later J tubes did not have the paddle anyway, neither Petromax or Anchor.
@Loe. Sounds like good advice. "Leave well alone." as the older and wiser people always told me. Thanks.
