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Valjoux 7750 mainspring health


Giuseppe

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Hello,

I'd like to hear some advice wether this MS is in good shape or if it should be replaced.

This comes from a 15 years old Omega Speedmaster Reduced, fitting a 7750, which has never been serviced before and stopped working.

I stripped the movement down to the mainspring since I thought in the first place I would have replaced it anyway.

But now I'm thinking that if it is in good shape it could be placed back in the barrel.

Should it be refitted the problem is I have no tool for MS, but that's a problem I'll deal with subsequently.

As you can see it is not flat to the surface and I remeber reading this is not good.

Any thought will be appreciated!

TIA Giuseppe

 

IMG_20181027_162303186.jpg

IMG_20181027_162317922.jpg

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It needs replacing. As you say its not flat, so it has become out of shape. When a spring is out of shape and it is wound up, it will rise and rub the barrel on the inside; this can cause poor flow of power to the train and erratic time keeping.  A new spring will come wound up and all you do is press the new spring in to the barrel. Just make sure before pressing in you have the spring the right way.  

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I would place a hefty wager that if you put that spring back in and ran tests on amplitude and running reserve, then replaced it with new, same tests, you'd see zero difference. True it's very slightly out of flat but not enough to have an effect. It otherwise looks perfect.

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    • in general this shouldn't be any change. but in general questions like this it be nice to know the specifics of the watch in other words how was it performing before it was cased up and what is it doing now.
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    • people be honest.... Swatch is evil for the watchmakers and repairers, BUT not everything in watches from Switzerland is from the Swatch-Group. As far as i know, Selitta got sacked by Swatch as a Movement-Assembler for them and they started to produce Movements in their own Name with slight Modifications. As far as i know, they sell Parts to the Market for their Movements. In most cases, if a ETA-Movement fails, it is a valid Option to replace it with a Selitta Movement, which i consider the Solution for this Mess with the Swatch-Group...... I have no Connection to anybody at Selitta, but being a Swiss-Guy, i still like to have Swiss-Made Watches, but not from the Swatch-Group.   ok ? regards, Ernst
    • Just one more greedy act by Swatch. They started a number of years ago here in the US..cutting off supplies to watchmakers that could build complications that many Swatch houses couldn't even touch. Old school masters who had gone through some of the most prestigious houses in the world. Otto Frei has some statements on their page about it. I tell all my customers to avoid new Swiss watches like the plague,..unless they just want an older one in their collection that still has some parts out on the market, or they have really deep pockets and don't mind waiting months and paying through the nose to get it back. Plenty of others to choose from..IE Seiko,..or other non-swiss brands Even a number of Chinese brands are catching up with the Swiss,..and I think that in time, their actions will be their downfall
    • Yes. If that's not what you are experiencing...start looking for something rubbing. A 1st guess is that one of the hands is rubbing against the hole in the center of the dial. Especially if you now have lower amplitude in face up/ face down positions.
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