Sub loses 6 minutes in 3 hours after settin time.

[Texas1971]

Hello! Maybe the learned folks here can give some advice. Thank goodness for such great people and forum!


Allow me to describe the problem:
- Watch is set to the exact time using US Naval Observatory atomic clock
- After 8 minutes it loses 1 minute, however the second hand is exactly on time
- After one hour the watch has lost 5 minutes, but the second hand is exactly perfect
- After three hours the watch has lost 6 minutes

Here is the strange part:

- After 4 hours the watch has not lost any more time and it remains 6 minutes slow for the rest of the day
- The second hand stays on time perfectly

It seems like the minute hand gets stuck in "slow gear" for about three minutes before it gets up to speed?

Any descriptions of what is going on would be helpful. Thanks Again.
Sub 16610 W series ~1995 was just purchased used and "serviced"