Hello people, I have been tinkering with an AGM 3927 for a while and have been having problems with yellow flames outside the mantle. It had this problem on its first fire up and my initial thought was that the jet was worn. I changed the jet for a spare and the was no change. Assuming I had two worn jets I changed the generator for a new Coleman one and still the same problem. Have I been unlucky with a duff generator or is there another issue that I have overlooked? I can only guess a blocked burner. James
Hello James, i have exactly the same lantern as you, AGM 3927, I have had no success getting it to burn right, it lights, then goes up and down from bright to very dull, i have had the whole fuel valve out three times to clear out any obstructions that might be inside the fuel body but no success, changed the generator, no better luck, i have no idea why its like this, maybe yours needs a complete fuel valve clean by removing it and flushing it with better success than me, i will wait and see how you go or what advice comes
@outback boy I agree your pulsing issues are some sort of blockage somewhere, I have read that the internals of these lamps need to be spotless for them to run well. The fuel feed pipe in mine was blocked, I hit it with a blowtorch and used a wire brush bristle to unblock the tiny hole in the bottom and then flushed it as best I could. Mine does not pulse just runs really rich. My generator was initally blocked as well. Hopefully soon we will both see the light. James
Definitely "burning rich" but the flame pattern suggests low pressure as well though I'd still double check the air tube and burner for cleanliness before pulling the valve/fuel feed for re-examination.
Looks to have an air obstruction. Most common is spider webs and mud daubers. Restricted burner screens are often seen as well.
Thank you @Henry Plews and @Toby Garner looks like you were both correct. I changed the burner for a spare with some 500cp butterfly mantels. The yellow flame issues are solved but it does still have the look of a lamp running at low pressure. For now I will leave it running and see if it settles down on its own. @outback boy your pulsing issues I would guess are a blockage in the generator where the heat from the mantle affects the pulse. If it's not the generator I found that a bycicle pump with a rubber end for pushing onto the valve did fit the chamfer where the generator fits quite well and was handy for unblocking mine and checking air flow.
Try increasing the pressure a little further to see if it brightens/whitens up or gets dimmer/more yellow. That'd determine whether its due to a less than optimized fuel-air ratio or simply a lack of fuel supply to the burner. If it brightens up upon increased pressure, then the cause would be the latter. If it gets dimmer or becomes more yellow, then its due to either an improper fuel-air ratio(too rich/lack of air) or a poor mixing in the mixing chamber.
@MYN Thank you for your advice on mixture symptoms. I have removed the valve assembly and managed to get slightly better air with bycicle pump test. I also shoved a bycicle spoke up the generator hole in the original burner. On firing up I initially only had one mantle burning, now have two but one with yellow flame. Think I need to get the ultrasonic cleaner out.
Thanks for the advice James, after three complete valve removals with little improvement i put it aside in disgust, maybe the ultrasonic cleaner might get to the fine passages inside the valve body
From the previous picture, it seems you're having some obstructions in the burner/mixing tube too. Since you have an ultrasonic cleaner, use strong lye solution as the bath liquid. Optionally, make it hot as well. That'd help loosen up most of the unwanted stuffs that are in the burner/mixing tube. You might also not be getting full vaporization of the fuel as well. Another clean-up of the generator would certainly help. There might be too much coke or carbon build-up on the inner surface of the gen.
The burner has had an overnight soak in cider vinegar followed by a quick buzz in the ultrasonic cleaner immersed in a hot cider vinegar solution. The fuel feed pipe has had a good pricking from my primus stove prickers until I could get the biggest one in. Checking with a pump gave me a good blast of air on my chin so it was time to fit some more luxor 200/300cp mantels and fire it up. Much better, thank you all for your help and advice.
