Can't keep my AMNPS lit in my Masterbuilt XL

Discussion in 'Propane Smokers' started by moose8327, Sep 4, 2011.

  1. Hi all (and Todd)-

        I am having issues keeping my AMNPS lit in my Masterbuilt XL. I started by drilling a series of holes in the base of the smoker and set my AMNPS over these holes (12 in all). No luck. Yesterday I modified an air intake on the side, at the bottom right next to where the AMNPS sits. Still no luck. I'm running out of ideas, and don't really want to put anymore holes in my smoker. [​IMG][​IMG]

    Any suggestions would be greatly appreciated. It would certainly make my overnight cooks a lot easier. Thanks in advance to anyone with a suggestion.

  2. smokinal

    smokinal Smoking Guru Staff Member Moderator OTBS Member ★ Lifetime Premier ★

    Are you using it to hot smoke or cold smoke?
  3. Hot smoke only so far. mainly for when I do butts and briskets.
  4. smokinal

    smokinal Smoking Guru Staff Member Moderator OTBS Member ★ Lifetime Premier ★

    Todd should be along to give you the answers you need.
  5. tjohnson

    tjohnson Smoking Guru Staff Member Moderator Insider OTBS Member SMF Premier Member

    Hey Moose

    Where are you placing the your AMNPS?

    Guys with a GOSM place it adjacent to the intake vent, so intake air has to pass thru it


    Are you lighting it with a torch and letting the flame burn for at lease 5 minutes before you blow it out?

    How about a better pic of the inside of the Masterbuilt XL

    I'm at the lake for the weekend, but do have limited internet access

    You can always call me @ (952)412-0484

    Last edited: Sep 4, 2011
  6. dvermi22441

    dvermi22441 Newbie


    I am having the same problems with mine as well.  i have the AMNPS and the Masterbuilt XL.  I think the problem is that the Masterbuilt doesn't have an intake other than the hole that the burner comes through so so most of the oxygen gets used by the burner.  The AMNPS did great when i cold smoked but would not stay lit when hot smoking. 
  7. nwdave

    nwdave Master of the Pit SMF Premier Member

    It is difficult to find the right spot for the AMNPS in a propane smoker, because as you've discovered the combustion of propane also uses a great deal of oxygen.  I don't have the XL so I'm not aware of it's vent system, but I do see in the picture above, a vent, that appears to be on the side.  My GOSM has two side vents.  The first thing I did was remove the deflector plate of the preferred vent, then created a shelf of sorts to rest the AMNPS on, as far back from the burner as possible.  I had to wrap the shelf in foil to act as a heat deflector because without it, the pellets would ignite prematurely.

    Here's some vues that may help you:


    My GOSM isn't very pristine, but she cooks just great and I don't want to jinx her.


    A very early picture in the tests to show: yes you can get smoke.


    Yes, you can get smoke.  Truth in viewing, this was taken during a cold smoke.  I did notice and Todd confirmed in his tests, that "smoke" visibility is different between hot and cold smoking.  Cold smoking, you'll see the above.  Hot smoke:  you'll see what's in the middle picture.  Apparently, in the hot environment, smoke becomes more transparent.  I don't know why other than to say the heat has something to do with it.  You're still getting the precious smoke we all desire.  You have to remember, the AMNPS and earlier versions (dust) were intended for cold smoking, but many of us are adapting it to hot smoking.  It can be done, but each individual smoker seems to present its own particular problems.  BTW, before someone asks, the glass in the GOSM door is a modification I and some others made so we could keep an eye on the Q'ing process, without opening the door all the time.  If you decide to mod your door this way, be sure to get oven rated glass.  It'll handle the temps you'll see with a propane smoker.

    Any further questions?  Just ask. 

  8. tjohnson

    tjohnson Smoking Guru Staff Member Moderator Insider OTBS Member SMF Premier Member

    Roller came up with an awesome solution for using an AMNPS in a smoker without adequate intake vents

    I tried the same method in my MES 40 and it worked awesome!

    Here's a Couple Pics:

    [​IMG]    [​IMG]
  9. frosty

    frosty Master of the Pit

    That is a pump for a fish tank correct?  I suppose your new holes in the bottom would be a good place to enter from, and the extra flow should really help.  That Roller is such an igenious fella!

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