On Friday, May 12, 2017 at 11:20:07 AM UTC-4, wrote:
My glider came with a PZL KI13 Compass - it turns fine but seems to be 90° out of alignment. I tried to adjust it and found I could choose between 90 or 180° of incorrectness!
It might be because of the Borgelt B40 vario I put next to it so I may not be able to keep this setup. I didn't notice if it was correct before changing the position of a couple of instruments.
Does anyone have a manual or instructions on how to adjust it?
I don't know if the (2) E-W & N-S screws should be turned 0-360 degrees (1 full turn) or multiple full turns etc.

thanks
Chris

Most likely the cause is external magnetic field from electric variometer. Try relocating the compass before any more effort elsewhere.