Bought Infinite switch WB21X5243. Adapter that fits in the knob sticks way out from face of stove no matter how much I cut back the stem. Any advice?
The adapter that you are referring to may not be a necessary part. It is for the purpose of the knob not fitting on the stem so you will want to make sure that the knob does not fit. If not then cut the stem on the switch back. It also appears that there are 3 different sizes of the adapter that you could use.
I've just replaced the infinite switch, WB21X5243, which I guess is a universal unit that replaces WB21X226. Everything works, but the adapter that fits my knob is the small solid "D" with an extension to fit over the square stem, causing the knob to stick out about 3/8" above the control panel. The instructions refer to a yellow bushing that goes over the square stem. I received an orange bushing that would go over the square stem, but its "D" shape is too big for my knob. I'm looking at the other parts in this kit, thinking that this assembly (bracket, threaded collar, nut) somehow gets attached to the switch inside the control panel (the extension on the adapter fits into it perfectly), but can't for the life of me figure out how to incorporate it into the install. I could attach the bracket to the switch, but the threaded collar won't fit through the hole on the control panel to receive the nut. And even if it goes that way, wouldn't I need longer screws to pass through the bracket and attach the switch directly to the control panel to keep it from turning with the knob? Heeeeeeelp!
The switch will attach directly to the control panel without the use of the bracket and nut. You would need to use the adapter that fits you knob and as long as the adapter sits flush with the control then this is the design of the part. If the adapter is not sitting flush then you will want to take another piece off of the stem.