Hi and my apology, I have not been here for months, my vintage drums kept me busy, playing and restoring same - so have not touched a watch for a while. I will better myself!
Now, a while ago I bough a Hamilton Brockton, presentation watch from Columbia Records (had the great Dave Brubeck Quartet under contract). Since I don't stock any parts for the 770 grade "family", I gave it to my watch tutor who is very good actually. He did a full COA and now it runs fast when fully wound. He does not know why (yet). He wanted to replace the spring but knowing me that is a definite no-no, he answered that for himself. Also lacking logic from my view, the watch wasn't doing that before (but it was very dry and dirty). So my next best idea is to give him my Stafford with a 770 so he can try that spring. But does anyone here have a clue what the problem could be? Thank you kindly & best regards/Chris

Hi Chris,

Without seeing the watch is hard to say many things can cause this. Putting the watch on a modern timing machine will give you best indication, my first thoughts are to remove the mainspring and measure it carefully check that the correct one is fitted often people will put a stronger one in believing it will cure problems or at least allow for sale as ticking and I suspect you may hear it knocking on occasion, fully wind the watch and listen to it carefully over a period of time for irregularity. Also demagnetize it, check hairspring for flat and flow of motion, then try the other 100s reasons it could be