Adjusting B&W Nautilus Mid range drivers

I have a set of N803's in my situation that were received with one driver seriously overtightened somehow. Someone I know that installs B&W's explained to me even though they're factory set that sometimes after you get them into your listening room that the mids need tweaking to balance out the soundstage. Does anyone know what the lb/ft setting B&W recommends is optimum? Where do you get the right tool to set it? Right now I'm running strictly analog using a new Benz Micro Ebony 3H phono cart and it hasn't fully broken in yet and can't tell whether the table needs slight adjustment or my FST drivers still do. I hear huge differences with just minor turns of the screw mostly in how deep and wide the soundstaging gets and the balancing of upper frequencies that seem to be out of balance due to the compression of the mid range driver and it's interaction with the bass drivers and tweeters. Has anyone encountered this issue and what did you do to justify it? Responses are greatly appreciated.
do you have the manual? I just set them somewhat the same and left it like that long ago. Didn't use any tools.
The screw that plugs the hole in the back needs to be taken out. You only adjust with the turns of that big round aluminum thing.
From B&W's website:

There is a large aluminium slotted screw at the back of my speaker, behind the FST midrange. What is it for and should I adjust it?

In many products, our FST midrange unit has an unusual mounting arrangement, where the driver is mechanically isolated from its enclosure by flexible gel components in the fixing arrangement. To optimise the isolation, a single securing rod is used that runs from the back of the driver to the back of the enclosure. The tension on the rod is controlled by a large headed, straight slot screw at the back of the enclosure, and this in turn controls the pressure on the flexible gel parts.

The amount of tension varies between different models and in some cases it is necessary to prevent excessive movement of the driver should it be exposed to impact in transit. In such cases, notably 800 Series products having the sphere/tube midrange enclosure, a clamping disc is fitted over the screw head, held in place by a crosshead screw in the centre. On installation, this clamping disc and centre screw should be removed in accordance with the pictorial instructions on the label fitted to the assembly.

It is important that the tension on the rod is set correctly. It is preset at the factory and should not require adjustment, except if the driver has to be removed for one reason or another, but sometimes it may get altered by mistake. This may be because one's natural instinct is to have a fiddle to see what happens, but occasionally removing the transit clamping disc has been known to loosen the main screw if it has bound itself in the thread.

If either of these has happened, please refer to your local B&W dealer to have the tension reset correctly. We recommend that you do not attempt this yourself.

N803nut, I have the same problem with a pair of 804s. I wonder could you tell me how you resolved the problem? Did you just go with a 'best guess' or did you find out how to set them 'correctly'?

Thanks and regards,

Yes B&W said loosen up the midrange screw till it's finger loose then retighten it till you feel it start to give resistance and then give it a half turn. Then you should play it for 10-20 hrs to reseat.
Great, thanks very much!