Slow down Asian 7750?

[DR3M3L]

Hello!

I have just gotten my first rep, a Breitling Navitimer 01 with an A7750 21600, and it's running quite fast... It gains 3-5 minutes per day. It runs faster when i wear it, and slower when stored dial down.

I would like to regulate this, and I am sure there are good guides here, but I can't find them...?

Could somebody point me in the right direction?

Rickard

 

[KBH]

3 to 5 minutes a day sounds like either the hairspring is hung up on itself or the movement is magnetized. You can check magnetism with a small compass, if you have one. Also, when you open it up to adjust, look closely with a loupe at the hairspring and try giving it a puff of air with a hand blower if it looks tangled.

Also you might try giving it a good whack into the palm of your hand a couple of times first before getting into the movement and see if that helps. It often untangles a hung up hairspring.

Here's the way to adjust the 7750:


Do not mess with the other tab, only the one shown it figure A.

 

[PaBrBe]

Thanks!

Gave it a few whacks, and set the time, we'll see what that does!

The hairspring, that is the spring that is below the balancewheel, right?

On the QC images it had good results, +2 secs/day, does that mean anything at all?

Rickard

 

[KBH]

Yep, that's the hairspring. More than likely that's what happened during shipping. Good luck.

 

[PaBrBe]

This did not fix it on the first try, it's still running too fast. It seems to run significantly faster while being worn, does that mean anything?

The good news is that the whack trick fixed an old automatic Seiko I thought been seriously damaged when it got banged a while ago!

I'll see how the Breitling does over night, and then it may be time to open it up...

Rickard

 

[PaBrBe]

Hello!

I think it runs better now, but not quite accurate enough...

If stored on the side, crown up, it will differ one or two seconds over 7-8 hours, but while being worn, it will gain 5 seconds per hour.

I guess I have to regulate it to make it slow down when I wear it, but how do I best store it?

Rickard

 

[Thomas_G.]

There is an error in the movement. Such difference between wearing and non-wearing should not be. There must be a mechanic flaw, best would be a watchmaker to check the amplitude. Can be a dry escapement, or dry balance wheel bearings. Or a mainspring problem....