Newbie quesyion

[gary17]

Hey

Does this spring look right size for this barrel.? 

Seems big. 

It's a seiko cal 9007a.

Cheers

Gary

[aac58]

The size looks correct to me, but not the shape. Once it gets to the external coils it shouldn't create a gap.

[gary17]

Hey thanks. 

What can I do about shape. Is it a case of unwind and then rewind. Or is there a problem with spring? 

Cheers

Gary

[Jon]

The spring size looks about right... 1/3 spring, 1/3 space and 1/3 arbor.

It might be a tad too long, but better a bit longer than shorter, as a shorter spring is more powerful and might cause over-banking

Take the spring out and you'll know if there is a problem with it or not, otherwise your just guessing. Personally, I always change the mainspring for a new one, because if there is a problem with amplitude etc later down the line, you'll find your trying to diagnose a fault when it was staring you in the face all along, for the sake of spending a tenner on a new spring!

Also, you'll need an anti-clockwise mainspring winder to get the old spring back in, if you were to use the old spring and the most common mainspring winders are clockwise, so you might have problems there as well

Edited May 1, 2020 by Jon

[aac58]

This is a 7005 MS, it's the same as a 7009. It looks like yours.

In my opinion your spring is bent, so I don't think unwinding and rewinding it will correct it. But I don't know how much will that affect the performance of the watch.

Edited May 2, 2020 by aac58