Yellow flame on Coleman 424 at low heat setting

Discussion in 'Fettling Forum' started by rogerzilla, Oct 7, 2012.

  1. rogerzilla

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    I've just rebuilt an eBay Coleman 424 suitcase stove. It runs well, with no yellow flame at the burner even during startup, but if I try and turn the main burner down to a low simmer I get a yellow flame coming back out of the manifold. Is this normal due to the low velocity through the jet, or does it indicate a gunky generator? I have ordered a new one but for the time being I've cleaned out the old one as best I can.

    This isn't due to fuel leakage past the jet threads - I've fixed that. This is only there at simmer.
     
  2. DAVE GIBSON

    DAVE GIBSON Subscriber

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    those Colemans,i have at least six,run so well even after lots of wear and tear that it has to be gunk in the generator.without a good blast of fuel running thru it at a simmer setting any tiny bit of a deposit would screw up the air-fuel mix
    i belong to the "let it run" school of stove repair,auto carb cleaner in the stove fuel and fire the stove up and run the thing until i get a blue flame..if that fails then buy parts..
     
  3. bajabum

    bajabum R.I.P.

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    You might also run a pipe cleaner thru the manifold, you may have some cobwebs in there...
     
  4. rogerzilla

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    The manifold should be clear - it's been washed in hot soapy water and blasted through with a hosepipe (and quickly dried in the oven to avoid rust). I suspect it's just the generator. The previous owner was running it on unleaded petrol.
     
  5. bajabum

    bajabum R.I.P.

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    Water will not dislodge spider webs, they are very strong. Only physical methods will work.
    YMMV...
     
  6. itchy

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    Before you replace the generator, try cleaning the one on the stove. I had a Coleman where the generator was so clogged fuel would not even flow through it. After a good cleaning it works great. On the other hand given the time it took to clean it, and assuming minimum wage, cleaning it cost 3x what a new one would have cost.
     
  7. rogerzilla

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    It was the generator. Runs sweet as a nut with the new one, and will turn down to the tiniest simmer. These are marvellous stoves, aren't they? The clever fuel/air tube makes all the difference when starting up - not like a single burner stove, where you light and stand back!