Since the LT25 already had 6* of down thrust, I wouldn't add anymore or change incidence. Your just overpowering a high winged trainer Crash.

Heck with mine I felt I was WAY over powered and I was definitely over propped with an OS FS 30 with a 10x6 on 15%. I couldn't even fly the thing level until I pulled the throttle back to idle going down wind and once going up wind it felt like an on/off switch the way it ballooned or sank everytime I touched the throttle.