Caliber 89: douby on power reserve

Dear Sirs,
do you know which is the standard power reserve of IWC caliber 89?

I'm experiecing on my IWC MArk XI that it stops after 15-18 hours even if it seems to be fully/completely hand-winded (after 7-8 turns of the crown)... Since it does not seem to be standard behaviour do you have an idea of what could be the problem?

Best regards and thank you

Cal 89 PR should be 36 hours...

I have never actually measured the full PR of my Mark 11, but I know for sure it is over 24 hours.

My Mark 11 runs 36 or so hours>

Also, I have to wind the crown a lot more than 7-8 turns.
Perhaps there is a problem with the mainspring, sounds like it needs a service.

Regards.

Caliber 89: douby on power reserve

Hi,

As a watchmaker I must first say that it's not possible to diagnose precisely the problem you've described without examining the timepiece inside at the bench.

Having said that, one or more reasons can be the problem though not in any particular order.

• movement once had a "shorter generic" mainspring replaced
• movement is gummed up due to no service in many years
• crown is clogged making it difficult to wind up the watch in full

There could be other reasons as well so, in my opinion, your watch will need to be totally disassembled by a professional watchmaker and have all the parts checked for wear and whether they are original. This procedure is normally done as part of a complete overhaul.

To conclude, I strongly recommend that you have your IWC Mark 11 timepiece serviced by none other than the IWC factory in Schaffhausen. Your local AD or official service center can arrange that for you.

Regards,
Jack Freedman