You took your Seiko off on Friday, and on Sunday it had stopped. Is it broken? Almost certainly not. An automatic watch runs on a spring that is wound by your movement, and once that energy is used up, it stops. Here is why your Seiko automatic stopped and how to keep it running.
How long should it run off the wrist?
| Movement | Power reserve when fully wound | Can you wind it by hand? |
|---|---|---|
| 4R36 / 4R35 | About 41 hours | Yes, turn the crown clockwise |
| 7S26 (SKX007) | About 41 hours | No, rotor only |
| 6R35 | About 70 hours | Yes |
| 6309 / 7002 (vintage) | See the reference guides | No |
Note the words fully wound. A short day of desk work may not fill the spring, so a watch can stop sooner than these figures.
Restart it the right way
- If it hand-winds (4R36, 6R35): unscrew the crown if it is screw-down, then turn it slowly clockwise. Seiko says turning counterclockwise does nothing and turning past full wind will not break the spring.
- If it does not hand-wind (7S26, 6309, 7002): give it a gentle side-to-side swing for a few seconds, then wear it.
- It may not start at once. Seiko notes the spring’s force is low at the start of winding. A gentle swing gets the balance moving.
- Set the time, then the date. Avoid changing the date late in the evening or at night, when the date-change mechanism is working; your manual gives the exact window.
Why it keeps stopping
| What you notice | Likely cause | What to do |
|---|---|---|
| Stops after a day or two off the wrist | Power reserve ran out (normal) | Wind it, wear it, or use a winder |
| Stops even when worn daily | Not enough wrist movement, or needs service | Wind fully each morning; if no change, see a watchmaker |
| Stops and runs very fast before | Magnetism | Compass test, see below |
| Hand-winds but dies within hours | Worn mainspring or dry oils | Service |
Seiko recommends wearing a 4R-series watch for more than 10 hours a day, or winding it fully at the same time every day if you don’t. If your watch was also gaining time before it stopped, check it for magnetism with our running-fast guide.
Do you need a watch winder?
Only if you rotate several automatics and hate resetting them. For a single Seiko, a few turns of the crown in the morning does the job. If you do buy one, Barrington lists 650 turns per day, bi-directional, for most modern Seiko movements.
Learn the terms power reserve and hand-winding in our glossary, or compare movements in the movement comparison.
Frequently asked questions
Is it bad for an automatic watch to stop?
No. Letting it stop and restarting it does no harm. You only need to reset the time and date.
How many hours does a Seiko automatic run when fully wound?
About 41 hours for the 4R36 according to Seiko, about 41 for the 7S26 per Caliber Corner, and about 70 for the 6R35.
What watch winder setting should I use for a Seiko?
Barrington Watch Winders lists 650 turns per day, bi-directional, for the 4R35, 4R36, 7S26 and 6R35.
Leave a Reply