Zenith stops when engaging the calendar

[AxelSLK]

Heyo!

Once again I turn to you kind knowledgeable people for help. 

i have been battling a zenith 2542pc for a few months now. Some of the issues I have battled so far is broken screws, lost click spring, broken incabloc spring, loose automatic rotor and now I have issues with the calendar works. (Some of the issues is my own doing hehe)

To the point. Fully serviced the movement to the best of my knowledge (keeping the old mainspring), got it on the time grapher and it seems to be running fine after some adjustment. Generally about 260 degrees amplitude in both DU and DD but I noticed that the watch stopped around 9pm with a lot of power left (enough to make it through the night). I could either shake it so it kicked back up or I could turn the watch forward a bit and it immediately kicks back up.

 I took it apart again to check the calendar wheels but I couldn’t see any damage or dirt that could make the watch stop at a specific time. Put a bit of HP-1300 on the yoke where the calendar jumper mechanism “whatever it is called” touches. Cleaned the wheels put it together. Put the watch on the timegrapher and it works great when the calendar is not engaged but as soon as the time gets closer to 17pm it drops the amplitude to about 220-230 and it doesn’t keep the time as good as when the calendar work is not engaging. When the watch isn’t fully wound it even stops every 30min to 1h.

Do anyone know how I properly lubricate the calendar works? 

Do I need to replace the mainspring?

Could it be something wrong with the gears or something else that creates this issue? 
 

I have noticed that the winding gets a tiny bit heavier when it gets close to 6-7pm when the calendar works engages but I didn’t really think of it until I realized it was an actual issue.

What do you think?

[nevenbekriev]

Hi Axel,

Something makes me thing it has nothing to do with the calendar. To be sure, remove one of the calendar wheels and try without it

[AxelSLK]

2 hours ago, nevenbekriev said:

Hi Axel,

Something makes me thing it has nothing to do with the calendar. To be sure, remove one of the calendar wheels and try without it

Hmm you might be very right my friend. Unfortunately I think I will have to completely take it apart again and see if I can find anything.

any suggestions on what to look for? Or any suggestions when putting it back together again and how to oil the calendar system?

[nevenbekriev]

Just in case, remove the calendar wheels and look what will happen - if the watch starts to work normally and exhausts all the power reserve, then it is really from the calendar.