It just occurred for the third time in a week. I’ve taken photos each of the three times, which is how I figured it out.

This morning:


Three days ago:


About six days ago:



The watch was just serviced. Before the service, the movement was periodically stopping far more frequently (but I did not take pictures and hadn’t noticed this pattern). My watch maker was told. In fairness, the watch, when it hasn’t stopped, is now keeping time within one or two seconds a day.

I’ve worn the watch all week, with the chrono running, and these are the only three times it’s done this; otherwise, it’s been wonderful. Each time, the watch is less than one third down from fully wound. The movement starts again when I depressed the top pusher to stop the chrono.

I can’t believe this is a coincidence, these stops while flipping from 57 to 58 minutes. I’m assuming that there’s a specific problem in the train, that a gear is probably slightly damaged in one place, making this one particular spot problematic.

I’m going to show this to my watchmaker later this morning. In the meantime, what do you guys think?

 

The watch is stopping just when the minute counter is starting to be engaged. This can mean excessive friction in that part of the movement, or overall low balance amplitude.

Any idea what the balance amplitude is with the chronograph off and then on - what sort of drop is there?

 

Not yet. I think I’m going to leave the watch stopped for when I bring it in later today.

I use two watchmakers.

Number one is an old time guy, looks like he rode a Harley back in the day. He’s squared away my 1850’s marine chronometer and a dozen other time pieces for me, including other Speedmasters. They all come back very accurate. He follows my instructions about not polishing cases etc. He charges half of what number two (below) does and his turn around time is a week, instead of two months. But, he doesn’t provide printouts of the movements’ timings in positions or even a written invoice. He’s been around for at least 40 years in the same location and is in his 70’s.

Number two is a middle aged Asian (probably Chinese?) with a heavy accent. He’s very Speedmaster savvy and owns a pristine 2998 he showed me. He provides those movement timing print outs and readily sources obscure 321 parts. He charges twice what number one does and takes two months minimum turn around. His shop is spotless. He was recommended by a couple of OF members and has proven to be excellent so far.

This watch was serviced by number one. I hate parting with a favored watch for two months.

Don’t you think it’s odd that it stops in exactly the same position on the minute counter each time?

 

@Archer :
Btw, I’m finally picking up my Lemania-Omega Speedymoon later today, with the ‘adjusted’ Lemania movement, from number two watchmaker. I’m assuming I’ll get the positions printout to share with you, as you asked some time ago.

https://omegaforums.net/threads/shi...nding-lemania-omega-speedymoon-arrives.73485/

 

Maybe the fitted mainspring is not the right one, thus the lack of power when the watch is winding down? Please let us know how the situation evolves, this could be interesting for other people as well

 

I will. I’m hoping I’ll have more info later today.

 

I had the same problem immediately after my watchmaker swapped hands on my Speedmaster. When I went to collect the watch we joked about his fear of something breaking on the 321 while in his custody.
Went home and tried the chrono and it stopped after 58 seconds.
Went back and showed him the stopped watch. I can only guess what went through his head as he normally does not touch the 321, and also after the discussion we had earlier about customers always blaming him when something breaks.
Anyway, it was a loose screw that stopped the gear train from moving freely at the minute counter. Took him no time to open the watch, tighten the screw, and reassembly. The watch works perfectly again.
Sometimes its a small thing.

 

Odd? No not really. It might be significant, but to me that fact that it is stopping when the minute counter is changing, and when the watch has been running for several hours already are more important.

Sure there could be a small burr on a tooth of the sliding gear assembly, but the fact that this happens at a time that requires the most torque that this movement will require, and when the watch has run down for a time, point to possibly a more fundamental issue for me.

Rogue screws...not an uncommon thing unfortunately...



Had this one come in recently and this screw was the immediate problem.

Cheers, Al

 

@Archer
That one was quite obvious. I have been wondering if there are specific torques or even loctite or similar to keep screws from coming loose?

 

You would not use Loctite on movement screws, but yes Omega does publish tightening/loosening torque specs for the screws on many movements, like the 1861. For example the screw that was loose in the picture I posted above should have been tightened to 2.80 cNm. And yes there are screwdrivers with torque handles for them (Bergeon Tork Speed for example, if you want to pay $2200 for a set of screwdrivers), but honestly if you do this long enough you know what the right amount of torque is for a given screw.

 

I look forward to the outcome.
My -69 occasionally does this and also a Heuer Camaro I have. They're fine if you don't use the chrono but it seems when the chrono stops at '58' it backs up and stops the whole thing!.

 

I had a similar situation with a Universal Geneve (cal 285) and my watchmaker had to do a lot of fine-adjusting and testing to get it to work properly. I think that he would make an adjustment to fix this problem, and it would cause some other problem. And he had to test it overnight in order for the problems to occur, so it really dragged on. (Sorry, I don't recall the details, but it's not important. He got it fixed in the end.)

 

So, story closure.

I was using the old time guy to service the watch. He’s clearly knowledgeable and long time experienced.

I did have to go back twice, and was getting disheartened. I gather that 321 movements are more ‘delicate’ and require greater assembly precision than 861s. (@Archer : please clue me in!) One smart thing I did do was not touch the watch every time it stopped, not winding it or stopping the chronograph, so he could pull it apart at the stoppage and adjust. (I’m very lucky that his shop is walking distance.) Of course, there was no charge for the subsequent visits.

(He’s now serviced a number of my 321s without a problem; he’s also previously serviced a number of 861s, Rolexes, vintage wristwatches, pockets watches and a marine chronometer of mine, all without a hiccup. I gather that, in buying watches from around the world, even in pristine condition, you can’t be sure about the state of the movement — even if the movement looks beautiful.)

Anyway, I’ve had the watch now for a couple of weeks without a single problem. And it keeps good time too, within a few seconds a day. You’ll notice that I’ve replaced the chrono second hand; it’s still luminova, but now it’s the correct style.

Closing shots. I love the CB case. I love that it’s a 321 with old style chrono buttons. And I love that it’s luminova. I wear it when I sleep.

So, it all worked out. This was $5.5 on eBay a few months ago.



I do wish it had a real stepped dial, but I don’t think I’ll go to that trouble.

Oh, I added the bracelet, which, I think, really makes these vintage Speedmasters.