Hi All,I have a 16s Model 1899,PS Bartlett that has me stumped.I took it down and ran ran it through my ultrasonic cleaner.Found no problems so put it back together,installed a new alloy mainspring.Wound it up and it gained 40 minutes over night.Before cleaning it was losing 3 or 4 minutes a day.Marshals catalog calls for a 2227 spring.Hairspring is between regulator pins,regulator in center.I have no way to de-magnetize it.Hair spring coils are not sticking together so didn't think that was it.Need some ideas to pursue.Thanks.Norm

UPDATE,Installed old mainspring and still runs fast but only gained about 7 minutes over night.Norm

Norn,
Check and make sure you you didn't lose a balance screw during your cleaning process..

Can't be that.I cleaned the balance by hand.Norm

I would have agreed with Gary on the balance screw, but you say there all there. Whom worked on it before you? Check to see if the balance bridge Number is the sane as the watch and if you can, check the number on the cross bar of the balance wheel. Could be somebody replaced the balance unit just to make a sale and the wheel is off numbered for the watch. I would also poise it to see if it is the wheel causing the problem.
I can also believe it's a MS problem and the proper spring would fix it. Also, where was the regulator set when you opened it ?

I've owned this watch for almost a year.Like I said it was losing a little time so I cleaned it and installed a 2227 alloy mainspring.Regulator was in center when taken apart.With it in the center and alloy spring it gains about 5 minutes an hour.Put the old spring back in and it still runs way too fast.I've checked hair spring a dozen times and can't find any thing wrong.I know I'm missing something but can't seem to find it.I does run with good amplitude.I don't have any thing else to do so I'll keep plugging away.Thanks all for help.Regards,Norm

Well if the numbers match for the balance system and the wheel is OK, I would still question the MS. It sounds like you are just getting to much power to the train.
It never hurts to demagnetize but I don' think thats the problem.

Hi Pat,thanks for your replies.I re-shaped the hairspring a little and with old main spring it is running a little slow.Quarter screws are out a little so should be able to turn them in to bring it into time.Regards.Norm