I have a two weight Vienna Regulator Clock. It runs for months and then stops at 5 minutes before the hour. What causes this ?
I purchased this clock when visiting Poland in 1970 and paid $20 for it! It's a wonderful clock and I really miss it when it is not working. Many thanks for your kindness!!
I'm not an expert, but clocks have a pre strike mechanism (your clock will make a subtle "clunk" a few minuites before striking)this could be seized or warped.