Yoder Smokers YS 640, Operation Manual

29

Firebox and Burn Grate Assembly Maintenance

It is recommended that the 

fi

 rebox assembly is regularly inspected to be certain that it remains free of 

ash and debris which will ensure proper performance. 

The 

fi

 rebox is a fully welded structure that carries the burn grate and channels the combustion air. The 

fi

 rebox is bolted to the cooking chamber 

fl

 oor. The seams on the hopper wall and the 

fl

 oor of the cooking 

chamber are sealed with a high temperature silicone. Perform regular inspection of the silicone seal, 

particularly on the top side of the 

fi

 rebox along the hopper wall. If this seal is broken, remove the old 

silicone, clean the surface, reapply new high temperature silicone and let it cure. We recommend using 

Permatex 81160

 high temperature silicone or 

Sure Bond SB-188

.

The seating of the burn grate into the 

fi

 rebox is critical for proper grill performance. Begin by resting the 

right hand side of the burn grate on the 

fi

 re pot and then pressing down on the left hand side of the burn 

grate until fully seated. Once the burn grate is seated there is little to no movement in this assembly. 

Also, check to be certain that the igniter assembly is centered in the respective hole in the burn grate.

Stainless Steel Burn Grate

It is important to regularly check the combustion air holes located on the 

fl

 oor and sides of the burn grate 

for any blockage or build-ups. Using a wire brush or 

fl

 at-head screwdriver, scrape o

ff

  any build-up or 

debris.

Burn Grate Inspection

NOTE

: Only do this when the smoker is completely cool.

To ensure that the pit is burning e

ffi

  ciently, a visual inspection of the burn grate is required periodically. 

The burn grate should sit 

fl

 at against the back wall. Due to the 

intense heat that is created, the burn grate can change shapes. There should be no more than a 3/16” 

gap from the back wall to the burn grate. If a gap does exist, then it must be corrected to ensure proper 

pellet burning. To get to the burn grate see Page 16.

If the gap is greater than 1/8”, the steps below should be followed.

NO MORE THAN A 3/16” GAP BETWEEN

BURN GRATE AND BACK WALL.

BURN GRATE

NO MORE THAN A 3/16” GAP BETWEEN

BURN GRATE AND BACK WALL.

BURN GRATE

FIG 28

30

1. 

Start by removing the burn grate from the 

fi

 rebox and placing it on its top.

2. 

Next, step on the burn grate and apply enough pressure to bend it back to its original shape.

 DO 

NOT 

apply too much pressure or you will overcorrect the burn grate and it will not 

fi

 t back into the 

fi

 rebox.

3. 

Place the burn grate back into the 

fi

 rebox and check the gap between the back 

wall and the burn grate to ensure a proper 

fi

 t. If a gap still exists, then repeat steps

1 and 2.

FIG 29

FIREBOX

BURN GRATE

FIG 30