Pictorial: S-20 Stoker Assembly W/Part Numbers (DF520)

9460431 Machined fan housing

The description and part numbers in order, beginning at the top left of the picture and working across to the bottom left of the picture:

9433761 Damper shaft and pointer assembly
9431728 Damper plate
81004 Damper plate retaining screw
32791 Air indicator plate
83201 Drive screws
82811 Groove pin
9431878 Shoulder bolt
81505 Set screw 5/16 X 5/8” long
85001 Thumbscrew ¼ X 20 X 1”
81507 Set screw 5/16 X 7/8” long

The description and part numbers in order, beginning at the top left of the picture and working across to the bottom left of the picture:

9433719 Crank
81505 Crank set screws
9433732 Crank pin
9443087 Connecting Rod
35659 Retaining clip
31024 Washer ¾ OD X ½ ID (used on feed lever stud)
9437423 Key 3/16 X 3/16 X ¾”

4016 1/8HP motor, 1725 RPM
9451003 Fan cover plate
81520 5/16 X 3/4 Hex Head bolts
33766 Motor coupling
81108 Stove bolts 5/16 X 1”

37872 Gear Reducing unit and vent plug
9451007 Fan
81504 Fan set screw 5/16 X ½” long

9536410-1 Assembly spacer ring
9441329 Oil Pan
1430 Crank Handle
9536409 Bin Feed Pipe Collar
36006 Cleanout tag
DHL-N Coiler Nickel door handle

9437850 Clean-out lever for units without optional oil burner kit
9437851 Clean-out lever for units with optional oil burner kit mounted above the stoker
82505 Washer 5/16”
82705 Cotter pin
32037 Clean-out rod spring
9434370 Clean-out rod
9433723 Clean-out rod eye

The first step of assembling the S-20 Stoker is to install the Groove Pin into the housing. This pin is used to index the air tube and to prevent the air tube/pot assembly from turning when it’s joined with the stoker assembly.

The Groove Pin is visible in the throat of the housing. The Damper Disc is installed at this time.

The clean-out lever shoulder bolt, set screws, air indicator plate and thumbscrew are installed next.

The clutch drive assembly, oil pan and serial number plate are installed.

The connecting rod, crank and gear reducing unit are installed and aligned. The first step is to install the gear reducing unit. The clamp plate on the inside of the housing secures the gear reducing unit. Tighten the four bolts to a few foot pounds so the gear unit can be rotated, but with some effort.

Install the crank onto the gear unit shaft, with the key and one set screw. Align the top of the crank with the top of the shaft for a preliminary setting. Lightly tighten the set screw. Affix one end of the connecting rod to the connecting rod stud on the left. This end shows the casting number G1426 and is facing downward. Let the other end of the connecting rod rest upon the crank. It must be in the same plane as the crank. To adjust, rotate the gear unit.

The loose end of the connecting rod has some up and down play. When moved off the top and to the side of the crank, it should drop as much as it will rise above the top of the crank. If the up and down play is not equal, move the crank up or down on the shaft. With the crank pin, connecting rod end, and crank lubricated, insert the crank pin with a twisting downward motion. It should drop in easily.

At this point, if the connecting rod can make one complete cycle without the crank pin binding, (twisting the crank pin and moving it up and down during the full cycle), the gear unit bolts and the crank set screw can be tightened.

The next step is to secure the connecting rod to the feed lever stud with a washer and clip on the left side and to tighten the crank pin on the right side. With the crank pin fully tight against the top of the crank, lift the pin up about 1/32” and tighten the set screw. Double check that the two set screws and gear reducing unit bolts are tight.

Attach the motor cover plate to the motor ears with two stove bolts. The dust cover MUST be used and is shown installed.

The fan is installed and is spaced about 1/16” away from the fan cover plate and secured to the motor shaft with the fan set screw. The motor coupler is also installed.

The entire assembly is then bolted to the fan housing with three bolts and the motor coupling set screw is tightened to the gear reducing unit shaft. The motor is energized and the stoker is checked for proper and quiet operation.