Good advice so here's what I did: removed the minute recorder jumper spring - movement stopped. Removed minute recording wheel - movement stopped, disengaged sliding gear - movement stopped, Tonight I removed chrono wheel so I will see tomorrow if it stopped again. Though I doubt it will because as long as chrono function was not in use, movement never stopped. Never applied any lubricant to chrono or minute pivots or chrono tension spring. Minute recording wheel and sliding gear both would spin freely with puff of air prior to removal. Do notice amplitude of 188 at full wind during chrono engagement. Still stumped. Thanks so much for your help though.
You are directing to a member which had posted once only and joined just because of the issue, I suppose that is the same as you.
After removing the stem replace back and the crystal is removed with a 10cc syringe.