I bought a new Primus Express Spider II stove recently but it doesn’t seem to burn properly if I invert the gas canister. I use the standard screw-on type of canister and they work great in the upright position. Somebody has posted a video on youtube () which shows exactly how my stove burns so there must be others who have experienced this problem. Instead of burning evenly the flame sputters and then flares up and this occurs even after I have been careful to heat up the preheat tube before inverting the gas canister. Does anyone know what is likely to be causing this problem? Do I need to change the jet to use gas in liquid feed? I do a lot of winter camping and the option to invert the gas canister is one of the reasons why I chose this stove. Many thanks for reading and for any advice you may be able to offer. Ben
There is a reply from the videoposter, he solved the problem : "The jet nipple was blocked.After I cleaned it worked no problem"
In my experience, even new stoves tend to have debris from production in the tank and/or fule-line. Certainly this was the case with my Manaslu 96 and caused annoyance on its first field-trip.
My stove worked well after I cleaned the jet nozzle but has now developed the same problem again so I'm guessing there may be some debris in the fuel line. This may be a dumb question but what is the best way to clean the fuel line or do I need to buy a new one?
May be incorrect, but I would assume that you keep cleaning the jet/nipple and eventually the manufacturing debris will be removed. I am sure that eventually the problem will go away. You will most likely have the same problem if you buy another. You could disassemble it and dispense canister fuel through the tube. IN A SAFE LOCATION AWAY FROM FLAMES.
Friends have had similar problems with modern stoves from both Primus and Optimus. The cure has been as snwcmpr has said, remove the nipple and run some fuel through working any control at the same time. Really the only long term cure is to ditch the gas.
Thanks for the replies. I cleaned the jet nozzle again and tried to clean the fuel line by blowing some gas through with the jet removed. The stove still sputtered and flared with inverted canisters, however, so I returned it to the shop and got my money back. As a replacement I got a Kovea Spider. It's a little bit lighter than the Primus and packs away more compactly too. I took it out in the snow today and it works just great, even with with the canister inverted. I'm not so sure about the axe and saw alternatives. If you cut down any trees in England their Lordships will probably have you hung in chains at the crossroads, with a branch and a warning note to others tied around your neck!
@Ben Nevis I’ve come to this thread late and you’ve swapped the Primus for a Kovea but for anyone coming to this thread subsequently I’d offer THIS example of a Primus Express Spider operating happily not just on liquefied isobutane (inverted cartridge mode) but on Aspen white gasoline. It suggests that the stove is capable of sustained vapourisation of liquid or liquefied isobutane fuel and that maybe your example Ben had some issue with it to do with debris in the fuel line, pre-heater loop or control valve. John
Primus sell a multifuel conversion kit for the Express Spider and I'm sure you're right that if you get a good copy this stove should work really well with liquid fuels. I like the idea of using the stove with the Trangia windshield. I have an old Trangia 25 without the hole for the fuel line but I could probably cut one out and try that approach with the Kovea Spider.
