Sulli: about every 3 or 4 years I have to unstick that manifold heat butterfly valve on a 216. I had good luck by first cleaning the exposed "shaft" on both the weighted and coiled spring sides where the shaft enters the manifold. I used a Dremel wire brush, or a thin sandpaperstrip to lightly shine & buff the shaft clean first. That shaft often does have a small bushing that it rides into on the manifold.
As another version of Joes' candle wax method ....
I then use heat from a soldering iron , or small torch, to heat shaft and then rapidly cool that area with a few drops of Kroil. That Kroil should "suck" along the shaft and help free the bind as the shaft cools. I would caution that twisting the weighted end too much may snap the shaft, and watch for mushrooming the little slot on the coil spring end as you gently tap the shaft side-to-side.
{52Carl, I'm confused if the manifold butterfly is removed, isn't that permanently "heat off" ?}
