Hi all I am about to give up on this Primus 1020. You can see the result I get when lighting it. I have done the following: 1. Tank and all fittings pressure tested, it keeps pressure, no leaks 2. Cleaned vaporiser tube 3. Cleaned and cleared air tubes 4. Tried all sorts of mantles from Peerless to Petromax 5. Replaced fuel tip (jet) and pricker needle 6. Double pre-heating 7. Replaced packing in pricker control wheel shaft The problem persists and seems to get worse the hotter the lantern gets. When I replaced the pricker rod, I turned it down until it stopped before fitting vaporizer. Turning pricker control wheel all the way clockwise blocks fuel flow. When I try to limit the fuel flow with the control wheel, it does not help. My starting procedure is: 1. Fill spirits cup and light 2. With second pre-heat nearly burned up, I close the pressure release screw in the filler cap 3. Pricker control wheel in closed position 4. Pump 5-10 pumps 5. Open pricker control wheel slowly 6. Pump another 20-30 pumps
This shows all the symptoms of too much fuel or not enough air. Here are some questions to get more information. 1. You say you have changed the jet. Where did you get it from and what is the part number? 2. Is there any restriction in the air intake tube? 3. Is the air intake tube and mixing tube sitting firmly in the burner head?
@Pdebruyn You should also make sure that the mixing tube (J-tube) isn't glowing when the lantern heats up. I had a similar effect with an Optimus 200 and almost nothing of the most obvious helped (changing jet, burner, J-tube, hood, etc.), but only when the vaporizer was changed, the lantern worked fine. The strange thing was that all the mixing tubes during the experiments started glowing after almost exactly the same time, before the vaporizer was changed. We already started to call that lantern "Maxi-Pessimus", but finally it worked like an "Optimus" should.
Nils I can only think that the problem is the it may get too much or too little fuel from the fount. Is it possible to remove the fuel pick-up tube from the fount to check for obstructions? thanks
Martin The vaporiser is in very good condition, was cleaned as well. I cannot get the lantern hot enough for the mixing tube to glow? regards
Nils, the jet was ordered from Base Camp in the UK, it fits perfectly. I had the same results from the old and replacement jet. Air intake tube was cleared and is free of cobwebs and the like. It also sits perfectly on the vaporiser and burner head.
The fuel pickup is soldered into the tank and I would not recommend trying to remove it. With the vapouriser and the cleaning pinion removed, it is just a straight tube into the tank so it can be cleaned from the top. With an empty tank, fit the vapouriser assembly to the vapouriser fitting without the globe cage. Pump pressure into the tank and then put the top end of the vapouriser into a bucket of water. There should only be air coming from the jet and not from the sides. It's probably good, but it doesn't hurt to check. It is possible that it was a bad jet you received. It is not easy to measure a jet orifice, but it should be around 0.19 to 0.2 mm. No more than that.
@Pdebruyn You are getting too much fuel out from the jet. Check that its screwed in snugly and not leaking traces of fuel from the threads. If its a new jet, do ensure the orifice is not bigger than 0.2mm in diameter. If by any chance you can find micro drill bits in your area, then a 0.21mm or larger bit won't get through the orifice if the jet is good. If you have any smaller jets, you can also use them to test if the results are the same or improved. Primus jets have a special thread size/pitch, so this option is somewhat unlikely.
