Most decent winders are programmed to rotate enough to keep the watch fully wound, and not more. If you put a 7750 on a bidirectional winder, it will only be winding half as much as it should, and will gradually lose power. I have experienced this personally and my friend also had the same problem with a modern Breitling that has a 7750-based movement. Fortunately, my winder had unidirectional modes, but his did not, and he was really pissed off.
My winder has different modes so you can choose how you want it to rotate and how often. I guess it depends on the winder
What exactly does this mean? Do you mean the hand jumps on the start, or is erratic as it moves around the dial?
I mean the second hand not advancing with a smooth 8Hz movement but stutter now and then, catching up on the next tick. The hand of this Chronoscope was advancing with a rate of 4Hz constantly. I took a long exposure and couldn't believe it. Have to try to find it .
Yes, parts are available, and watchmakers know how to service it, but that doesn't make it a good movement. We see similar phenomena in many industries, where a dominant company foists its cheap, mediocre components onto the market. Just because they are common doesn't mean they are well-made, sturdy, robust, etc., and we should make the distinction clear.
Good automatic chronograph movements do exist (e.g. Zenith 3019), and I think it is unfortunate that the most common automatic chronograph movement in 2019 (even in decent brands) is so heavy, clunky, thick, and noisy ... and inefficient because of unidirectional winding. If your autowinder doesn't have a unidirectional mode, your 7750 will eventually run down while sitting on the winder. Just an unsophisticated movement IMO.
Adding photos of my Valjoux-based chronographs:
It’s an adjustment of the oscillating pinion, or to the friction for the chronograph wheel. Should be easy to fix at service.
