Trim sender change on a 1991 115 2T

[axolotl98]

Hi there.
Just changed my trim sender unit on my 115, the old one was broken for more than a year now.
2 things that I noticed. First, when I trim the engine all the way down, the Yam instrument shows the engine trim to be at position number 3 with the sensor repositioned to its uppermost position.
Tried to manually move the moving part of the sensor to its lowermost position, and the trim position showed 1.5...

Q1. Is there any way to calibrate the instrument to show zero, with the trim sender at its lowermost position ?
Q2. Considering that I have reached the limits of correctly positioning the sender on the engine, how can I lower the little moving bracket even further ? Can I dismantle it and reposition the bracket relative to the sender itself ?

Thanks

[boats.net]

The only adjustment you can make is with the mounting screws in slotted holes on sender. Recheck your model number and make sure you have the correct sender for your model motor.