Part identification for LeCoultre 480

[dibs1]

Hi all,

so I have a JLC k480/cow that was running strong for a while. 270 amplitude and +/-5 seconds a day. I noticed one day losing minutes every hour, but it continued to run strong on Timegrapher. I assumed it was a loose canon pinion so i tightened it. And the watch continued to keep time well for the day. Then I go to case it to finish up and the amplitude starts to drop in all positions but dial down (even dial down amplitude now is 230-240). And I don’t know where to go. I didn’t change or adjust anything jus the canon pinion. I tried reoiling capstones it helped a lot but still not running as strong. I had to replace the escape wheel in the original service a while back. And when I went to check for parts today I noticed there are two different escape wheels listed wondering if anyone could clarify that. And further instruct me on how to resolve this issue 

1109_JLC 480.pdf

[nickelsilver]

703 would have a cap jewel in the mainplate for one end, 705 would have no cap jewels.

 

Loss of amplitude can be a whole bunch of things, really hard to say without more info or seeing the piece. Adding oil to cap jewels might be over-oiling; if there is too much at the balance, for example, it could have run up the roller table and covered the roller jewel.