I have installed David Bushnell's U-2S and I am experiencing pitch instability problems. I have altered the .cfg as follows:

Pitch stability - was 2.002 and I've changed it to 1.000
Roll stability = was 1.833 and I've changed it to 1.000
elevator effectiveness was .501 and now is 1.000

The problem seems unaltered by these changes.

What am I overlooking ?

Gringo6,

If the pitch stability setting was already at 2, then this compensates for aspects of the dynamics that the author knew were making it unstable. Reducing this figure will make it less stable, so try increasing it (to 3 maybe, or even beyond) to see if this makes any difference.