crowmadic

Dave, I'm so glad you're going to ask him about the screw. I would have thought someone on TM would have answered this by now. I just did a "ballsy" thing that I might do with valves I can't get to stop sticking or dragging. I went ahead and bought a lapping tool and some lapping compound and used them on an old Olds Ambassador Cornet that needs a lot of work. The middle valve only went 1/3 of the way into the valve casing. First I took the lapping compound, smeared it on the valve as directed, and worked the valve in and out. I made some headway but not enough. After washing the compound off of the valve and the casing I inserted the lapping tool and expanded it without trying to cut any metal. There was an immediate improvement which lead me to beleive the valve casing was out of round or had some obstruction. After doing this from the top and bottom of the casing the valve went into the casing properly. Of course the objective is not to overdo it. But I can tell you that I wouldn't hesitate to do this again on any horn that gives me a valve problem that can't be remedied by other means. I wouldn't try this on extremely expensive horns. I'd leave that to the experts................let me know what you find out about the screw.........crow