Expected Precision of Omega Caliber 420 (1950s) After Recent Service

JwRosenthal · Oct 21, 2024

Art.
Mine was way off even just sitting on the dresser. I haven’t even tried wearing it yet since it clearly needs servicing.

Whomever did your service should be able to sort it out pretty easily. I’ve had this happen a few times with watches I’ve purchased online
Once was magnetized (did a demag and it was fine).
Another there was a drop of oil on the hairsping causing it to stick to itself (watchmaker cleaned hairsping and it was fine)
Yet another the hairspring got kinked up on itself and just removing the hairspring and letting it hang by gravity and putting it back in solved the issue.

Art. · Oct 21, 2024

JwRosenthal
Whomever did your service should be able to sort it out pretty easily. I’ve had this happen a few times with watches I’ve purchased online
Once was magnetized (did a demag and it was fine).
Another there was a drop of oil on the hairsping causing it to stick to itself (watchmaker cleaned hairsping and it was fine)
Yet another the hairspring got kinked up on itself and just removing the hairspring and letting it hang by gravity and putting it back in solved the issue.

That’s great to hear. I’ve never had that issue with my other Omega from the same era, which has a 266 movement. Hopefully, it’s nothing serious. I will post the updates here.

impaw · Oct 21, 2024

Art.
That's so awesome! What nice timepiece. Congratulations!!!

Thank you😀 Its a keeper for sure

The results are in
After 24h and 7minutes it has lost 6seconds.
So it lost more during the day with office activities etc, than at night (as to be expected I guess).
An impressive old watch😀

Art. · Nov 21, 2024

Just following up—my watch has been serviced, and it's running perfectly now. The timekeeping is well within the expected range.

impaw · Nov 21, 2024

Good to hear! Enjoy it👍

UNLucky · Nov 21, 2024

*edit, i didnt get to page 2. So I see now you've already learned everything I said. 😁 Well, maybe someone else will enjoy reading. Congrats on the time piece!!

I have a 1960s speedmaster and it's +/- 4-6 SPD with around 292 amp and .1 beat error. So it's possible to get a fairly accurate read after a service. To get the best possible, you'd need a timegrapher and patience, and then there are (I believe) 3 positions you should measure and adjust for for the best possible. However, just the 1 is good enough to wear if you dont mind losing or gaining a min or two each day. I'm not speaking to your watch or service, I just know that it is possible to get a good SPD on an old quality watch.