A few weeks ago at a garage sale I picked up a Gustav Becker 400 day clock with original disc pendulum. After cleaning movement, spring, etc. I installed a suspension spring I had on hand. It worked but was slow, very slow. I ordered the typical .0040 Horolovar spring and installed that one and now it is way too fast. I tried thinning the spring and maybe that will help but it is running real fast. The pendulum rotation is just barely 180 degrees and it is not fluttering, I have a beat amplifer. I've worked on these before and it seems to always be an issue for these to keep decent time, not even good time, at least for me. Up next is a Philip Hauck, I believe, 400 day, the one that has Anniversary stamped on the movement plate and dial with the arched brass top with what appears to be a sun rise with rays and has the smallish disc pendulum, not sure what to expect from that one. Any guidance with the Becker and upcoming Hauck would be greatly appreciated.