I uncovered in my selection of old stock I got from an auction an automatic Seiko chronograph 6139. I read a little about some problems these watches had, namely the clutch on the centre chronograph wheel and the seconds hand mounting.
I am not sure if my diagnosis is close: while the chronograph is running the watch keeps time pretty well (within a couple of seconds per day worn on hand). Not always, but more often then not, when the chronograph is stopped the watch slowly stops (say it takes 3-4 seconds). When the chronograph is released the watch starts running. The fly back button does the job properly, start/stop/restart button works well. The watch had issues with the hammer click (was too strong - not original hammer spring) but for the time being it is ok.
I did not disassemble the watch yet as I am waiting for the original hammer spring. So this is a little hypothetical/frivolous question: Is there a chance that the (weak spot) centre chronograph wheel needs just cleaning and oil rather then complete replacement? Parts for this movement are scarce and the centre chronograph wheel is unreasonably pricey and the wheel itself - as far as I found out is not serviceable. Any comment will be appreciated.
Picture for movement ID.
The dial looks good for it's age.
From my experience there is really much that can be done to improve the look of a vintage dial. Often what appears to be dirt is instead oxidation and cannot be removed without changing the appearance of the dial. I would stick to using Rodico and Q-Tips dipped in distilled water. If you do anything, be very careful and work very slow. Keep in mind the printing on the dial is often placed on top of the lacquer and it's the first to go when "cleaning" is attempted.
Thanks. That was going to be my first step. I asked because I was curious if the "resets wrong but advances right" was indicative of something specific that I haven't come across in discussions yet.
Worst case scenario, I line up the second hand and don't think about it much when the minute recorder advances.
I think you can just remove the hand and set it at zero when in reset position. If that doesn't do it there's a laundry list of potential issues, on which books have been written. Try that and if you still have a problem it can be addressed.
Thanks. Not broken, the balance cock spring is identical. Huge ping hazard though. These function very much like the usual Incabloc springs in that you release the legs and then lift the spring out of the housing. Thanks,