The kink was a bend in the primary air rod (item 61). The Defiant user manual shows the rod as a straight metal rod with no bends. The rod itself is held to the air shutter by a single support on the bottom of the air shutter and then two supports to make the hinge on the top. To assemble the air shutter one needs to pull the rod in backwards through the bottom support, work it to the two 90 degree bends and the slide through the top two hing holes.
Because of the bend at the lower rod support, the shutter would not go fully closed. If I loosened the set screw on the primary air shutter so the thermostat cable was loose (item 66) and just pulled the shutter shut by hand, it would pop right back to the partially opened position.
I found the Encore 0028 and 2140 service manual online. It is very similar in design to the Defiant. In the assembly instructions there is no mention of bending this rod. In fact, the instructions are to set the thermostat cable so that the primary air shutter is fully closed with the control handle at minimum heat position with the stove cold.
I also found that the primary air rod was bent over to keep the rod from backing out of the hinge. The Encore service manual mentions the rod should be held in place with a friction clip. There was no friction clip, rather the assemblers just bent the rod to keep it in place. The rod is 3/16" thick and the process of bending it in place could also affect the operation. I had to use a vice grips to bend it back enough to get the old rod out.
I purchased a new rod and thermostat cable through my dealer. The rod did not come with friction clips, so I ordered one through McMaster Carr.
You can check the condition of the air rod by simply removing the two screws in the picture below. The thermostat cable will still be connected, but you can carefully side the assembly out, but not all the way. This will allow you to at least inspect the condition of your air shutter.
To do the full replacement you need to pull the cable out from the set screw. If there is a copper sleeve, you will need to cut it off to get the cable out. Then you can fully remove the rod and air shutter. There is a special arrangement to thread the cable through the rod, shown in the user manual. If you're lucky, there is enough cable you can just thread it through the replacement air rod and re-assemble.
To replace the cable, you need to remove the right air plate to access the thermostat. Make sure you tie a string to the old cable before you pull out, so you can easily thread the new one through the back of the stove.
Here is a link to the Encore service manual, you'll probably find it more helpful than my dis-jointed discussion:
http://www.increa.com/reverse/defiant-encore-stove-catalytic-replacement/Serv_Encore_0028_2140.pdf
