Movement slowing down from time to time

[BlueHarp]

Hello,

I'm wondering why a movement is slowing down from time to time, that is irregularly. It may work very well for several days but suddenly it loses several minutes within a short periode of time. Would that come from the barrel? The caliber is a France Ebauche 140C.

Thanks for your help

[JohnR725]

What is the watch doing at the time it's having a problem? In other words are you wearing this watch on your wrist Or is sitting on the bench in front of you when you notice there's a problem?

i don't suppose you have a timing machine? Always nice for helping with Trying to diagnose problems.

Then background history of the watch is this a watch you've serviced is it a watch you recently acquired the problem just suddenly pop up or has it been reoccurring.

Then for those of us who like pictures I have a link so we can see pictures of what your watch would look like where should look like. Because I was thinking if the problem occurs spread over day is perhaps a calendar mechanism but I see this watch doesn't have a calendar.

https://17jewels.info/movements/f/fe/fe-140-c/

 

 

[watchweasol]

Hi  Its just as John explains, that without history , pictures  etc its difficult to put your finger on the problem but just as an aside, Do you fully wind the watch and wear it or as John said leave it on the bench. At what point does it start to fail , after the spring has rundown a bit, Because it could be the spring is dry/dirty and sticking in the barrel, some gunge in a jewel, or a pinnion, an out of round wheel, basically a thousand things  more information required please..   all the best.

[BlueHarp]

It happens when I'm wearing the watch as well as when it is on my desk. The problem is that I don't notice what it's going wrong because the hands don't stop. I disassembled the movement a few weeks ago. It runs very well over a period of several days until it loses several minutes within an hour or two. The movement is exactly the one which photo has been put by JohnR725.

If the slowing down were continuous I would guess that there might be some friction on some parts or that I would have to set the regulator. On the other hand, if it happened suddenly at the same time every day, I would have a close view on the hands. But it works well over a period of several days and then slows down.

[Nucejoe]

1 hour ago, BlueHarp said:

It may work very well for several days 

So unlikely to be a worn gear or pinion leave.

 

2 hours ago, BlueHarp said:

 but suddenly it loses several minutes within a short periode of time. 

Could be loose canon pinon, loose hands, faulty hand set train,  excessive end shake on any arbour.

Did you not open the barrel? can be there.

2 minutes ago, Nucejoe said:

So unlikely to be a worn gear or pinion leave.

 

Could be loose canon pinon, loose hands, faulty hand set train,  excessive end shake on any arbour.

Did you not open the barrel? can be there.

also stick hairspring, or tiny hair, speck of dirt . 

[watchweasol]

As joe said did you open the barrel and remove the mainspring. My gut feeling is it’s sticking .