[c5sparkchaser]

Hey guys, I've got an interesting problem that doesn't seem to make much sense (to me, at least). I have a 6309-8210 with a 6309A movement that is running very slow. The "slowness" is not always at the same rate, sometimes losing 5 min/hr, sometimes 45 min/hr. To be honest, ithe watch may simply require a cleaning because I don't know its full history, but I wanted to throw the symptoms out there in case there was something that stood out as odd.

-- I'm pretty sure it has a good wind on it because I shook it for 5 minutes.

-- The weight rotates freely & easily and I can hear the mainspring being wound in both directions of weight rotation.

-- The balance wheel rocks back and forth quickly and at a regular rate. If I physically stop the balance, it immediately starts up when I release it.

-- When I manually set the time the hands glide smoothly and correctly in relation to each other.

-- Originally I thought that the second hand did not stop even when the hour & minute hands did, but I just saw it stop twice, in the exact same spot, several minutes apart.

-- The Day/Date wheels operate smoothly & properly and at the proper time in regards to the position of the hour & minute hands.

Thank you in advance for any help.

 

[c5sparkchaser]

Update

I tried the hairdryer trick to loosen up any thickening or hardened oil and that seems to have done the trick. The first time, I left the case back on (to limit the amount of dust in the case, but I don't think the heat made it to the movement because it didn't help. The 2nd time I removed the case back and heated the movement for 30 seconds. That seems to have done the trick, because it's kept almost perfect time for about 14 hours. It actually gained 15 seconds.