Coleman 424 Igniting/Flaming Query

Discussion in 'Stove Forum' started by hangell, Dec 2, 2021.

  1. hangell United Kingdom

    Offline
    Joined:
    Dec 1, 2021
    Messages:
    4
    Location:
    Wales
    Hi,

    Just discovered this forum after purchasing a 424 from eBay. Already found 2 threads that have helped regarding my stove and a leak it had on the fuel tank which after a quick tighten with a spanner was all sorted. I tried lighting the stove yesterday (Unleaded) but had no luck, kept getting fuel dripping out of the back of the U-bend which at one point ignited, bit scary, but swiftly cut off the fuel and pulled the tank away and blew it out.
    Today after some more searching on the forum Coleman 424 question about leaking I followed some advice to check the vaporizing is actually taking place and discovered that I possibly wasn't turning the fuel control enough, after 5-6 turns I was getting a mist coming out not 4 turns as the manual states.

    I connected the tank back up and tried once more and after 5-6 good turns I got a misty cloud coming out onto the burner area which I lit up. The flames were rather large but thought I'd give it a minute before messing around with the lighting lever and fuel knob.
    Next thing some fuel must have started leaking out of the back of the U-bend again as that then ignited, this is where I got pretty worried and cut the fuel off and blew everything out. The lighting lever was still pointing skyward so confused as to how enough liquid fuel was coming out to start dripping/pooling.

    Any advice here, and also, my wife is not amused at such flames so close to a tank of fuel, what are the chance of something going horribly wrong (i.e. - KABOOM)


    Many thanks
     
  2. Daryl

    Daryl United States SotM Winner Subscriber

    Offline
    Joined:
    Dec 10, 2019
    Messages:
    422
    Location:
    Sunny SoCal Grand Terrace
    Welcome and very happy to read that you are trying to learn about your stove, keep reading. Maybe go to Old Town Coleman Center and read what Frank wrote about stove operation theory. Others will be along to help soon or maybe before I finish. Do ALL your stove lighting OUTSIDE, never turn your back on them, keep wet towel handy, the list goes on, and you will/should be fine. Lighting instructions only go so far. Mist from burner is good , fuel dripping not good. In short you are flooding the manifold with liquid fuel. Try to keep burner flame at manageable height 6-8" by turning fuel knob on & off. May take a couple minutes for generator to heat & vaporize fuel, mist is not vapor. Once generator starts to vaporize fuel yellow flame will turn blue and you can turn leaver down. Might check your 'U bend' is totally clear also.
    Daryl sunny SoCal
     
  3. hangell United Kingdom

    Offline
    Joined:
    Dec 1, 2021
    Messages:
    4
    Location:
    Wales
    Hi thanks for the Welcome and advice.
    A little update, I did manage to get it to light although there was some dripping under the manifold it didn;t ignite and the dripping actually ceased after the burner was lit.

    Another conundrum, 2 actually:
    1) I couldn't quite get the flame down to a nice blue ring, until I lit the other burner, then both burners burned nicely. Once the second burner was turned off, I couldn't get a blue flame only a low yellow flame, I ever turned the control knob down so much that I actually turned it off accidentally.
    2) Second issue, once I had turned the stove off completely, I pulled out the fuel tank and could hear hissing coming from the generator, after a while the hissing turned to a slow drip. It's been 2 hours now and there is still a slow drip from the tip, assume my control knob isn't closing off properly and maybe it's time for a new valve and generator, I don't have the history behind the stove so unsure on age of the current gear. In the meantime though what's the best way to de-pressurise the tank to stop the dripping, open the fuel cap slowly? Thinking about it, could this dripping under pressure be the dripping I;m seeing from the manifold in the delay between me pressurizing and lighting......
     
  4. presscall

    presscall United Kingdom SotM Winner SotY Winner Subscriber

    Offline
    Joined:
    Aug 25, 2009
    Messages:
    11,008
    Location:
    Lancashire, United Kingdom
    That would prompt me to overhaul the valve, fuel/air pickup and generator, dismantling the parts to do so.

    Your use of unleaded petrol may well be compliant with the manufacturer’s designation of it as ‘dual fuel’ but the additives in pump petrol gum up those parts. ‘Dual fuel’ is a marketing ploy. If the previous owner has used pump petrol too it’s very likely that the symptoms you’ve described of erratic fuel atomisation on start-up and poor vapourisation subsequently are down to that.

    In the UK Aspen 4, Coleman fuel or - at a pinch - naptha-based panel wipe are the fuels to avoid issues like this.
     
  5. Majicwrench

    Majicwrench Subscriber

    Offline
    Joined:
    Jun 21, 2012
    Messages:
    1,470
    You are flooding the stove, are you lighting it with little lever in up position and then leaving it there for 30 seconds or so??

    And it should not drip from generator tip. That will, of course, end up flooding burner with liquid fuel. Valve is simple to take apart and inspect for debris.

    Issue with yellow flames is same basic problem, stove is flooded, opening secondary burner lets more air flow which improves burn. It is normal, even with a properly burning Coleman 2 burner, for the primary burner to burn yellow IF you open valve too far w/o the secondary open.

    Once stove flooded, it takes an amazing length of time for excess fuel to burn off.

    If you want to see if stove will burn properly, remove tank, make sure burner is dry. Leave outside, tip it around, something. Then pump up tank off of stove, install it, lever up, open valve a couple turns and light it quickly. It should light easily. Leave lever up!!! for a good 30 seconds. Then lever down, it might have to run another couple minutes to get up to temp.
     
  6. snwcmpr

    snwcmpr SotM Winner Subscriber

    Offline
    Joined:
    Nov 16, 2011
    Messages:
    16,666
    Location:
    North Carolina
    With tank/generator assembly removed.
    In a very clear and open area.

    Pump the tank.
    Turn lever UP.
    Open valve till fuel comes out.
    >Should be a mist.
    Turn lever down.
    >Mist should change to stream.
    Close fuel valve.

    Report back.

    Also. Clean the U-bend area, manifold, to make sure spider webs and wasps nests are not in it.
    Compressed air will not work. Wire, coat hanger, pipe cleaner, etc.
     
  7. Daryl

    Daryl United States SotM Winner Subscriber

    Offline
    Joined:
    Dec 10, 2019
    Messages:
    422
    Location:
    Sunny SoCal Grand Terrace
    To answer your second question about hissing generator it is more than likely your fuel valve is not sealing 100% letting fuel drip out. I always release the pressure in tank after flame is out. Just very slowly unscrew fuel cap and expect some hissing and fuel leakage. With no pressure fuel will stay in faunt. On paper you should be able to turn off knob and walk away, but things don't always work that way. Daryl
     
  8. Jim Lukowski

    Jim Lukowski United States Subscriber

    Offline
    Joined:
    Jul 13, 2015
    Messages:
    285
    Location:
    New Jersey, USA
    >>Once stove flooded, it takes an amazing length of time for excess fuel to burn off.

    As Keith stated, it tales a long time. I did this once with temps around 30, and didn't let the generator heat up enough before turning the lever down. In this case, it really needed closer to two minutes before turning the lever down. I found it quicker to remove the burner and soak up the excess fuel with paper towels

    As snwcmpr stated, if the fuel and air tube in the tank is functioning properly, you will see a mist with the lever up and straight fuel with the lever down. However, this is not an instant change. You may need to wait some number of seconds for the generator to clear before seeing the change between mist/straight fuel and vice versa. Cleaning the bunsen should be first on the list. It's amazing how bugs can get into tiny places and build their nests.

    For the fuel not stopping upon shutdown, it's possible that some grit is caught in the valve, but likely a previous owner thought the stove should shut down instantly like a light switch and cranked down on the valve, damaging the seat. It's an easy fix if that's the case, so don't let that scare you. When you shut the stove off, it's still burning off the fuel in the generator that's continuing to vaporize. I recently saw some old published advice from Coleman that when shutting down, to turn the lever back up for a minute first. Lever up will not only provide a fuel/air mix, leaving less fuel in the generator, but will be using up air in the tank at a quick clip.

    Also, take solace in the fact that Coleman wasn't cheap when it comes to safety. Although the flames may not have been far away, Coleman founts and tanks were not made with thin metal. Of course, and old appliance has to be evaluated if rusty inside, but yours is likely fine and probably has a liner in the tank to prevent rust.
     
  9. hangell United Kingdom

    Offline
    Joined:
    Dec 1, 2021
    Messages:
    4
    Location:
    Wales
    Wow, thankyou Guys/Gals for all the responses.
    I did as advised, and upon pumping up the fuel drip started again from the tip of the generator.
    After pumping up 30-ish times and fuel lever up I turned the knob, took around 5 turns for it to not be a stream of liquid and turn into a mist, once I then flipped the lever down the stream came on, but did have a bit of a rythym hard to describe it would pause every 2-3 seconds like when you pour liquid out of a bottle and air needs to go back in, don't know if that's helpful or even relevant.
    I will look to cleaning up the manifold and I will get on YouTube for some maintenance instructions.
     
  10. snwcmpr

    snwcmpr SotM Winner Subscriber

    Offline
    Joined:
    Nov 16, 2011
    Messages:
    16,666
    Location:
    North Carolina
    Thats great.
    That means the fuel pickup is working to switch from mist to stream, priming to run.

    How much fuel in the tank?
    Fuel pickup might be dirty?
    After the misting you need to add air again, after the misting. It uses some of the pressure to mist.
    Others can add more
     
  11. BradB

    BradB United States Subscriber

    Offline
    Joined:
    Aug 21, 2013
    Messages:
    1,705
    Location:
    Central North Carolina USA
    Make sure the tank is half full to 3/4 when lighting. Coleman stoves and lanterns often don’t pick up fuel well when near empty.
     
  12. Schnuppiepup

    Schnuppiepup United States Subscriber

    Offline
    Joined:
    Jan 8, 2021
    Messages:
    57
    Location:
    California
    From what you're describing, the fuel system seems to be working properly. There are two steps by you, the user, that are important:

    1) Fill the tank no more than 3/4 full. There needs to be an air/vapor zone at least 2 cm tall at the top of the tank. (There are air/vapor inlet holes within that zone.)
    2) While lighting, with selector rod pointing UP, DO run the stove for at least 1 minute with the selector rod pointing up. Thus: have fuel valve turned off, give 30 strokes to the pump, point selector rod up, open big fuel valve 1/2 turn, put a flame to the burner, and let the stove run like that for at least 1 minute.

    Now, you can give the pump a few more strokes, turn the selector rod down, and adjust the flame however you wish using the fuel knob.

    If you follow steps 1 and 2 above, with normal use, you won't have any flooding.

    One more thing, to address an abnormal situation. It's abnormal to have liquid fuel in a cold generator before lighting the stove. If there's liquid fuel in the generator, and you try to light the stove carefully following steps 1 and 2 above, you could still unknowingly inject the liquid fuel into the manifold and burner. Drat! Flooding: tall yellow flames, etc., etc. Liquid fuel could be sitting in a cold generator because (A) it was left there after a previous improper stove shutdown, or (B) you opened the round fuel knob with the selector rod pointing down with a cold generator, like when you were experimenting/playing with the stove. So, you can remove liquid fuel from the generator before starting the stove using several ways: Let the tank/generator sit outdoors with the jet pointing down for a few hours; liquid fuel should drip out. Or, unthread the jet from the generator, which has the added benefit of letting you drop the coil out of the generator and inspect or clean carbon from the coil and needle. Reassemble. Promise yourself that you'll never open the fuel valve on a pumped-up tank with the selector rod pointing down with a cold generator. Now you surely have a normal situation and can go up and follow steps 1 and 2.
     
  13. Schnuppiepup

    Schnuppiepup United States Subscriber

    Offline
    Joined:
    Jan 8, 2021
    Messages:
    57
    Location:
    California
    The following four conditions are NOT the cause of your flooding problem:

    I've seen this condition once or twice, and you've corrected it, and it wouldn't be the cause of your flooding.

    Turns of the large black control knob aren't a primary cause of flooding. Instead, the up or down position of the selector knob is always a causative factor. Five turns of the black knob might actually have been too much. Just 1/4 or 1/2 a turn of the knob when starting the stove is sufficient. Easy does it, at first. Then, after a couple minutes of blue flame, go hog wild with the fuel.

    Use of the second burner only diminishes the power of the flame from the primary burner. It doesn't affect the color. Maybe there wasn't enough air pressure in the tank.

    I've never needed to replace a generator on a Coleman two-burner stove, even on very old, heavily used, rusty stoves. I have, however, unthreaded a few generators and removed rust and carbon from the coil, simply out of fastidiousness and not out of need.

    Here, below, are three conditions that are unlikely, long-shot possible causes of trouble

    I've never seen this trouble, although I suppose it's theoretically possible that rust can be drawn up from the tank and can get between the mating surfaces of the fuel valve. Poor valve sealing here could (long shot) flood a cold generator and thereby flood the manifold and burner. Tear-down of the valve would be in order. Instead, I'm confident that by following the instructions in my previous post, you'll learn how to not flood the stove.

    I once spotted a spider nest in a manifold in a Coleman camp stove in storage. It didn't cause flooding.

    Running in vapor mode (selector rod up) might need to go for 2 minutes rather than 1 minute. If (A) the ambient temperatures are really low (freezing or below) and/or (B) you're using auto fuel rather than Coleman fuel.

    And finally, a few explications on what I said earlier:

    I described two ways. Another is to prime the stove the old-fashioned way, by (fuel knob turned off) dribbling a few CCs of alcohol or stove fuel on the primary burner, letting it burn to heat the generator, and then (with selector rod up for starting, as always, for a minute) slowly opening the fuel knob while touching a flame to the burner. Another is to prime by hitting the generator with a flame from a propane torch for a minute. You would use these unusual priming methods merely to get your stove generator "dried out" as part of your at-home stove learning.

    Along with carbon, there can also be fine-grained rust that has been drawn up from the fuel tank and deposited within the generator. This stuff can clog the jet.

    If all four of these conditions are present, you'll have flooding. If only one condition is absent, you won't. Interesting, huh? On many occasions, I've intentionally caused all four (unfavorable) conditions to be present so I could squirt fuel onto a trash burn in a firepit. The fuel jets out almost 2 meters. What fun. It's a little like having a pissing contest.

    I've owned and fettled on a half dozen Coleman two-burner camp stoves and operated them something like 300 times. Even nowadays, I still flood one occasionally out of impatience (not waiting the 1 minute) or by starting a stove after using a pressurized tank for a pissing contest/trash burn.
     
    Last edited: Dec 4, 2021
  14. hangell United Kingdom

    Offline
    Joined:
    Dec 1, 2021
    Messages:
    4
    Location:
    Wales
    Apologies for the silence, really appreciative of the replies, sadly due to the great British weather and work schedule I haven't been able to get out and have some more practice with the stove.
    That's interesting as the wife want's to buy me a new Valve & Generator to Christmas so I can "start new/fresh" with the stove, maybe I'll try and dissuade her and look to clean it up myself when I get chance.
     
  15. snwcmpr

    snwcmpr SotM Winner Subscriber

    Offline
    Joined:
    Nov 16, 2011
    Messages:
    16,666
    Location:
    North Carolina
    I replaced a generator when I was impatient removing a coil for cleaning.
    As said, if the generator is cleaned, and no damage to it exists, I also do not see the need to replace it.
    Patience is a necessary tool in our stove fettler too box.
     
  16. hikerduane

    hikerduane Subscriber

    Offline
    Joined:
    Mar 1, 2010
    Messages:
    7,812
    Location:
    Plumas County, CA
    I've seen or heard about more than one stove and a few lanterns that flooded due to spider webs or another obstruction, so @snwcmpr, is correct on that count. I've never run a Coleman suitcase stove with the start lever up for even a minute, I do get some yellow flame, but not concerned about that, pressure goes fast with start lever up very long. My old Coleman 454 needed a couple attempts at a mud dauber nest to get stove to run blue.
    Duane