Hi all. I having been working on servicing a few PWs I purchased to practice on. One in particular is a Waltham 16s. It has been fully disassembled, thoroughly cleaned, oiled and reassembled. It runs well for about three hours after being fully wound and then stops. Is this a symptom of a bad mainspring or could it be something else? Thanks for any insights.
Most visitors online was 1660 , on 12 Dec 2020