I've been sorting through spanner sizes required to do any repairs / maintenance on my stoves, as I'm not happy about using even the best adjustable spanners on brass stuff which might have been undisturbed for 50 years or more. The Optimus 80s are easy - 8, 10 and 12mm cover the packing nut, SRV and burner - but the Burmos is a bit tricky. It looks like the burner needs either a 3/4" AF or 19mm open ended spanner, and the whacking great nut on the screw-in pump looks like a 15/16" AF. I understand that the British motor industry started using Unified thread fasteners from about 1930 onwards, and standard Unified hexagon sizes are 3/4" AF for 1/2" dia. bolts and 15/16" AF for 5/8" dia. My other question is the thread of the burner, as I would like to change it back from the roarer burner currently fitted to a silent burner as was originally fitted. Could I use a burner meant for another British stove, such as a Monitor? Would one for a 2 pint Primus or Svea fit? Any advice would be much appreciated. With best regards, Gunner
I respect your view on that, certainly. In truth, I’ve not had any camming-over or damage of spanner flats using BAHCO adjustables. Ironic really that the spanner packed with a stove was a metal stamping typically in relatively thin gauge metal. Result, many a chewed burner hexagon. As collectors with an eye to sound fettling technique we’re inevitably more fastidious than the stove’s original owner, most likely. Burner threads will be common to your Burmos and Swedish equivalents, something the British manufacturers often made a point of saying in the catalogues. ‘96’ stove type vapouriser and tank mount threads often weren’t compatible British-Swedish however. John
@presscall - many thanks for the advice, John; I do use the Burmos a lot for cooking at home, and the racket from the burner is a bit wearing after a while , so that info will make it much easier to source a suitable silent burner. Re. the smaller stoves; I've just received a rather nice Shinabro 340 (off E-bay), and checked the spanner sizes for the burner (the only part with hex fittings) - 17mm for the lower part which screws into the tank, and 19mm for the upper part - so I'll work on the assumption that if I do need to make any replacements, they'll be Metric threads, too. And the original spanner which came with it for screwing in the burner? A mighty 2mm thick! Fortunately, I still have a hefty 14/17mm o/e Honda spanner, which came with the 250 RS I bought 40 years ago, and it's short and stubby enough to fit into the Shinabro's steel case With best regards, Gunner
