Worked on unsticking a heat riser valve over the weekend. Successfully, I think. It is still a little sticky at the full open and full closed positions. My question is this: Are the holes in the manifold for the shaft bushed. It appears that on the end away from the counterweight that a bushing is still frozen to the shaft and is turning in the hole while on the other end the shaft seems to be freely turning in the bushing. The valve is welded to the rod. Should I attempt to get this apart? Are bushings available to re-bush this? Appreciate any reply