Flame under Masterbuilt XL (not in the burner area)

Discussion in 'Propane Smokers' started by mojo13, Jun 28, 2012.

  1. I went to use my Masterbuilt XL for the first time this year and tried it out last night before todays smoke. I started it up and the flame seemed very small so I let it go for a while and all of a sudden there was a fire under the smoker. It looks like it is coming from where the burner pipe meets the gas pipe. The pipe has holes ( I assume for safety) and it seems like gas is leaking from there and catching fire. I have to turn the gas all the way up to seem to get any flame on the burner when I do this the fire catches after 10 minutes or so. 

    I have tried to push the pipe in farther but doesn't seem to move at all. It worked before I put it away for the winter. Just wondering if anyone has any ideas. Might have to do the Boston Butt in the oven today....this is a sad sad day
  2. s2k9k

    s2k9k AMNPS Test Group

    Since you said you put it up for the winter, that makes me think the burner tube could be clogged. Spiders just love to spin webs in those tubes. I would pull the burner out and inspect and clean everything. Pipe cleaners work great for this.
  3. michael ark

    michael ark Master of the Pit

    I would say something has made a home in the tube.evict them!:biggrin:
  4. I have a very similar problem with my MasterBuilt 30" gas smoker. It worked fine for the first 10-12 times then I noticed that I was getting flames where the control valve pipe enters the venturi. The flame is not there all of the time. When I first light the burner it seems fine. But after a few minutes the gas around the venturi ignites. The flame sometimes will go out (but the burner its self is still ignited) and then it will come back. It really seems like there is too much gas going into the burner but I have the problem even on the lowest settings.

    I've inspected the burner, per the suggestions here. It it very clean. Any other suggestions would be appreciated.


    Love the site, by the way.
  5. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Take the burner out and flush it with water, from both ends.... A visual inspection is not adequate.... Then blow it out with air.... even air from the blow end of a shop vac.....   Dave
    Last edited: Oct 30, 2012
  6. Thanks, Dave. I'll give it a try. So the reason for the flame at the venturi tube is excess gas that cannot make it thru the burner, correct? Does the burner get gunked up with smokey tar if I use my cold smoke generator? I guess that it could given how badly everything in there gets coated with that tarry gunk.
  7. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

  8. yardbird

    yardbird Meat Mopper

    Exactly what mine did when I get spider in the venturi tube. I didn't have a spider brush (yes you can buy those, that's how common this problem is), but I did have some 12 gauge stranded copper wire. I stripped the end and untwisted it so I could splay the wire ends out like a bottle brush. Stuck it in the venturi while twisting it between my fingers. VOILA! Spider webs get gathered up and come out with the wire.
  9. Thanks for the info. I'll remember that, probably this spring when I get back into outdoor cooking. It's getting close to winter here in Northern Utah.
  10. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    GC, evening..... Since you have recently joined the forum, I will let that statement slide by, like a sled driven by a 12 year old on ice...... 

    This forum, reading it daily, should tickle the taste buds into dragging out the smoker in the foulest weather known to folks in Utah..... 

    I will predict you are smoking in less than a month...  If I am wrong, remind me....  I love being wrong..... Another valuable learning experience is always welcome....   I figure every day I learn something keep me looking at the green part of the grass....

  11. porkboy9000

    porkboy9000 Newbie

    Funny, first google hit sends me here and nails my problem. Second use of my new Masterbuilt and there's flames coming out around the gas control knob. A few turns of the screw later, and those little white crispy spider nest things see the light of day.  Two cue tips duct taped together did the trick... and now I'm smoking again!
  12. arwen73

    arwen73 Newbie

    I created an account just to say the spiderwebs caused this problem for us too! Our smoker is only a few months old and I was so upset when I fired it up, temp wouldn't get over 125 and then flames came shooting out from behind the control panel. Hubby was skeptical- even with a flashlight he couldn't see webs in the burner tube- but he ran a pipe cleaner through and there they were! We're happy to be ready to smoke again this Memorial Day weekend! Thanks to everyone who posted!
  13. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    [​IMG]  ...   Glad we could help....  Good smokin'.......
  14. Just created an account to say thanks! This was 100% the problem I had. Got up early to start the first smoke of the season for me, two pork shoulders with some Memphis dust rub, and holy flames! I hope these turn out well :)

  15. ksanger

    ksanger Newbie

    My large Masterbuilt gas smoker was leaking too last Sunday.  Unfortunately I didn't stop my smoking until it burned up the knob and starter.  Now I'm rebuilding it.  I've bought a new hose, starter, and regulator as the old regulator is crimped to a burned out hose.  Still have the same issue and it looks like it starts behind the valve between the valve body parts.  Tests okay until you turn the valve on and block the output.  Then the body is clearly leaking gas.  Less than 8 months old.  Used a dozen times, and I'm on my second tank of gas.

    When I took the valve apart I didn't see any gasket between the two body halves.  Nor did I see any worn gasket on the valve shaft.  Looking  for a replacement valve next.  Plus another source of heat and smoke.
  16. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Maybe....  make a gasket out of a beer carton....   That compressed paper is what many gaskets are make of...   I used it many times when stuff has broke down...     Beer boxes have ALWAYS been handy for some unknown reason...    LOL...  

  17. ksanger

    ksanger Newbie

    Update on Masterbuilt 30" Smoker Burn Up.

    Well I rebuilt the smoker by replacing the gas line, regulator, and igniter.  Lit it up and the valve still leaked.  Tore the valve apart and cleaned it.  Checked the valve and valve body using an eye loop to make certain it was clean.  Added a drop of 3in1 oil to lubricate it.  Replaced the spring with a slightly longer spring.  First time I lit it up it still leaked.  Pressed in on the knob hard and it hasn't leaked since. 

    Called MasterBuilt on the Friday before the 4th of July.  They sent replacement parts on warranty but they took one week to arrive.  I haven't used the new valve yet.  There is no gasket on the new valve either. 

    While we were repairing the smoker we bought the Char Grill Side Grill/Smoke box and plumbed it into the MasterBuilt using 5" round heat ducts and caps.  This allows using charcoal and hardwoods while tending the fire once per hour.  Still needed gas to get the smoke box to 165F for smoking sausage.  Tried a 500W electric charcoal fire starter burner but it wouldn't get me to 165F either.  I'll be looking for a 1000W burner next.  Bought a PID solid state relay controller on Amazon to monitor the electric burner.  When we're finished we'll have a gas, charcoal, and electric smoker.

    For the 4th, we made 10 lbs of Venison Beer Sausage, a 25 lb Brisket, 9 racks of St. Luis Ribs, and 4 filets of Salmon.


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