I have one of the above. Runs well for about 5 mins then slows down. When I "prick" it, it comes back to life again. However I am using kerosene fuel, as I have got lots of it.
Is this a recent purchase? Did you clean the tank? Is the kerosene clear and clean? Have you run it more than one tank? I would empty the tank of fuel and look at the fuel. I use a quart yogurt container as they are very light colored and shows all the sediment. If dirty, I would clean the tank out. Then I would replace with clean fuel. Not a lot, but enough to run it to empty. If that does not work ... On to other solutions.
A common reason of that behaviour is loose soot in the burner clogging the jet every few minutes - if so, the cure is to detach the jet nipple and blow air through the burner while heating it outside - this will produce flames and sparks so it should only be done in a fire safe space - then clean out any residues from the "back side" of the nipple before re-fitting. AB DCS
To snwcmpr. No.... Yes....Yes....Yes. Have checked "clearness" of kerosene. Looks fine To Lennart... How does the nipple come off? Never had to do that before.
The nipple is threaded - you need a suitable tool - roarer burners are usually impossible to take out the nipple from without a tool made for burner jet nipples. Here is a thread dealing with tools... Stove Tool Question
Thinking about it....Been reading up on the fettling tips as well as your input ( Thanks guys/gals ). There is a lot of "pitting" on the burner tubes. Think the best solution is to buy a new burner with jet. So where can I get one?
@manfrommanchester, burner replacement seems a bit excessive for want of a simple de coke. As above when you prick the jet you'll be poking stray bits back behind the nipple which'll only come back to haunt you. A.nipple can be removed without a wobbly tool but takes time and effort with whatever tools you may have available. It is worth doing apparently, although I've never bothered myself, just pricked till the bits finally clear. I now have a few stoves with rather over sized jets.
Use of the articulated tool for jet removal is not difficult. Much quicker than a wrench or pliers. It is like a 'u-joint' of a drive axle. Easily obtained because they made so many of them. How to Remove Jet from Primus 210? For the simple price of a subscription you can post a request to buy one on our Trading Post. 9 USD per year. And you can then have access to the catalogs and other information in the Library. Ken