Some months ago, I purchased an n"Emerald" grade 6/0 Waltham in not running condition. After disassembly and cleaning, it was running and keeping good time in all positions, except face up. Naturally, I assumed I didn't look carefully enough at the upper balance pivot and jewels. So last weekend, I snatched those parts out, and took them apart again. Under a 15x loupe, the pivot and cap jewel in the cock look good, and the balance pivots both look good. So I put it back together, thinking maybe there was a spot of crud that I had missed, and dislodged it in disassembly. Now the durned thing runs for about two minutes and then stops in every position. I am thinking this is progress, but in a negative direction. Anybody got any suggestions?

Well - after no replies, I assumed I was "on my own", so did a careful inspection of the balance assembly under a 15X loupe. It looked like I had gotten the end block on the balance spring set a little high in the cock, so loosened the set screw, and nudged the block downward, until it was flush with the surface of the cock. That seems to have made things much happier. It is still stopping occasionally, though, so I suspect I didn't get all the old gummed up oil out from beneath either the balance cap jewels or the escape wheel cap jewels. Looks like I shall have to disassemble it once again. This whole trip would be a lot easier on a size 18 watch. Learning watch re[pair on a 6/0 makes for a steep learning curve.