Major surgery for my Masterbuilt GS40 gasser

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Original poster
Mar 4, 2014
Joplin Missouri
After a couple years of heavy use on my gasser, I decided to go a step further than just the necessary mods on the chip box and water pan. I did both of those in the beginning and have to say it made my life much easier and turned out some good grub, but I like to tinker with things and just couldn't leave well enough alone. Here is the surgery so far with more to come before it is released from the shop.

First on the list was to scrap the lousy vent on the back and fab a

real smoke stack to help with some draft.

Rear vent gone

Smoke stack built and attached

Rain cap built ... adjustable in up or open position

Rain cap in down or closed position

Hopefully this one addition will help provide some good draft which will

help with my second mod.

Next on the list is my upgraded version of the mail box mod. I have used the mail box with my AMNPS for both

cold smoking as well as hot smoking and just figured I would try to clean it up a bit.

Ammo box sliced up a bit. Not an original idea but I sure do like the cheap cost and ready made size

Top vent added that will come thru the floor of the gasser

Ammo box fits in very nicely between the legs on the side above the cart that

was built to move around easily. (custom chip box in background)

Smoke inlet fits in nice beside the burner. Still need to fab a hood to double as

a smoke diffuser and grease shield, but its moving along nicely.

The last mod that I have done right now is something I have wanted to do for a while.

I robbed a side burner off an old grill and decided to transplant it to try to help achieve

a lower temp for my jerky and sausage.

Old burner out and ready to retire

Transplant cast burner with brass diffuser ready to fab a mount

Transplant burner mounted and ready to go

Transplant in place. It looks off center in the pic but that is just the angle.

It is really centered. This burner is rated at 10k btu as compared to the

original that is 15k btu, so I am hoping it will help with a lower bottom end temp

of around 140 as well as still hit a top end of 275. Shouldn't be a problem.

Keep your fingers

This is where the surgery sits right now. There are several more operations that are scheduled and should be very beneficial. Stay tuned for more updates very soon.

Till then....embrace the smoke.
Thanks JckDanls 07....I just cant seem to ever leave well enough alone with something. I do agree though, it should have been an outpatient. The wait is going to send me into withdrawls if I don't get it done soon. Stay tuned for more updates by the end of this weekend.
Hey all fellow smokers. I found myself wayyyyy side tracked and never took the time to finish my post about the surgery on the gasser. It all did get done and I am very very happy with the results. New life for the gasser, although I am not sure I can call it a Masterbuilt any Follow along and I will cover the rest of the mods that I did to make a more versatile smoker.

At last post I had the old burner out and new brass burner installed. I will pick up there and list everything to the finish.

Here is the new burner installed and the first fire. Great low blue

flame. I have also installed the ammo box for my AMPNS under the

floor and have it vented into the cabinet with a large opening

so there are no restrictions to the flow of the smoke.

 New burner with high flame.

Heat diversion plate installed. Smoke diversion plate installed

above the heat plate. I don't know if it is really needed, but figured

why not.

New drip pan installed. I "borrowed" a loaf pan from the wifes

kitchen to replace that crappy little round can they give you from

the factory. This is much better.

New handle fabricated. I hated the flimsy latch that was from the

factory, so it was relocated to the scrap pile.

Rear wind shield in place to help control those breezy days. Installed

hinge to be able to reach the drip pan easy and that handle should

look familiar. I repurposed the side handle that was by the door

latch that I removed. Works like a charm.

Side wind shields installed.

Side shelf fabricated and installed. I added folding braces so

the shelf could be laid flat to be able to put a cover on.

This is my low end temp and high end temp on the first test fire.

I am happy but know it can do better both ways. The smoke stack

I fabricated for it is adjustable, so I set in playing with it. I ended

up with a low end about 130 and a high end at 400. I am very

very happy now.

All said and done I would have to say the mods were very beneficial

for what I do. I can now cold smoke my cheese, run a low fire and smoke

the bacon, sausage and snack sticks I make as well as salmon without any

worries about getting too hot. And then all I have to do is turn the knob

and waaalaaaa I have 250 to 300 for the ribs, butts, brisket, fatties, turkey

and what ever else I have a hankering for at the time.

I have done several smokes on this now and love being able to control the

smoke independent from the flame. The AMNPS is the bomb and

use it entirely for my smoke now with this setup. This may not be for

everyone, but if any of these mods help someone or even give them

a better idea of how to do it then its all worth it.

Thanks for looking and happy smokin .....
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