adjusting potentiometer

[CTDiesel at aol.com]

I know this is a very difficult job but....I have a new (used, good) air plate potentiometer and cannot get it adjusted within specs.  #1 and 2 should be greater than 4k ohms and #2 and #3 should be less than 1k ohms but even with the ovaled holes i cannot get those numbers.  I could get them with my old potentiometer.  The air plate is located where is should be as well.  Has anyone BTDT?

Thanks
DJ