will's watch pages
Care and maintenance of watches: 2 - Regulating a watch
A mechanical watch mechanism can run fast and slow - more so than quartz movements. It is possible to make adjustments to its rate by moving the regulator in the movement to the left or the right. Moving it towards the F or + (plus) sign makes the movement go faster; moving it towards the S or - (minus) sign makes it go slower. However, even the slightest movement of the regulator can make a big alteration to the rate of the watch. Unless you have the necessary skill, my advice is to have the regulation done by a trained watch repairer. The picture shows a typical regulator mechanism (from a Marvin 520 movement). As you can see, the pointer is right in the middle of the "F" and "S" marks, meaning that the movement is running at the right rate and needs no adjustment. If you're tempted to buy a watch over the internet, always ask to see a photo of the movement. If you see the pointer hard over to one side, then it may be that the watch has reached the limit of its regulation. It may need stripping, cleaning and further, more sophisticated work to get it at the right speed.