Primus experts ahoy... I have Primus 1320 lamp that has been conververted to kerosene one. Now I'd like to reconvert it back to original (spirit) one. So what actually do I need to change as a part of this reconversion? - To my understanding the air intake pipe should be shrinked having approx 5mm (??) air intake hole only - Burner, is it the same for both versions? - What about the jet? Existing jet has marking Primus 8145. Cheers!
Yes, air intake is only 5mm. The burner is the same as for 1020. The jet on my example is not marked with a number so I can't help you with that. I measured the cleaning needle at 0.36mm if that's of any use. Are you sure the existing jet is 8145 ? A 1020 jet is marked 6145.
@Henry Plews A pricker diameter of 0.36mm seems huge for a lantern jet Henry, but maybe not for one fuelled by alcohol eh? All my lamps are paraffin or benzine so I’ve no experience of alcohol fuelling. John
Yes, 0.36 is almost a . . . well, perhaps not a nail but near enough a veneer pin. I've just measured the cleaning needle from the alcohol conversion kit for a Radius 119 and it's only 0.31mm
A mere 0.31mm! With fuel consumption correspondingly up on the other fuels. Paraffin stove jet territory.
@Henry Plews You are right, the jet is 6145. The first number was challenging to identify. How the air intake mod is done with original alcohol versions?
I've never lit my Primus 1320 but I did once install the alcohol conversion kit on the Radius 119 and ran a tank of alcohol through it. As far as the naked eye was concerned, the lamp was just as bright as when using paraffin and there was no odour which would make it suitable for indoor lighting. The down side was fuel consumption, if I made notes, I can't find them but from memory a tankful (1ltr.) lasted around 7.5 / 8 hours, Radius claim 1ltr of kero will burn 12 hours in a 119 and that's about what you get.
@TommiL the air tube restricter is a brass insert which is held in place by crimping the end of the air tube. The brass is approximately 0.76mm thick. I checked the size of the hole with a drill bit - it is less than 5mm but more than 4.5mm.
I have reconverted a couple of 200cp lamps (392 and 394), and one 300cp lamp (1325). The information I have is that the jet for the 1320 series should be 0.32mm and the air intake hole is 5mm. Measuring 0.36 for the cleaning needle just doesn't seem right. How well does it work? My 1325 with 0.32mm gives just as much light as a 1025, so my assumption is that it is correct. I have used worn out 1020 jets and had then drilled out to 0.32mm. I then use a 0.3mm acupuncture needle to make a cleaning needle. One of the German collectors (sorry I can't remember who) put together a table of jet sizes and it lists 300cp for ethanol as being 0.3mm.
@Henry Plews Thx for sharing. The bottom part of air tube is bit "fatter" and actually ideal for a brass insert. I need to figure out how to get one made. Indeed, burning alcohol is nearly odourless and that's the biggest value of them. Maybe my final Q: Should the be inside of the vaporiser pipe some sort of mesh for fuel preheating purposes?
I don't think so. My example doesn't have any mesh in the vapouriser. The 1020 also does not have a mesh.
Yes there is a mesh disc attached to the cleaning needle rod. You can see this in the Primus catalogues from 1950 (both the English and Swedish catalogues have the 1320). The cleaning needle rod screws apart just below the grooves and the mesh disc is then attached. The question is whether the cleaning needle rod in yours has been changed to a 1020 item or not.
I've remeasured the needle on my 1320 and sure enough, it's 0.32. Perhaps I need my eyes testing, here are images of the mesh disc as described by @Nils Stephenson
