what prop would you recomend for an sc .75 engine (2 stroke) on a high wing trainer 6gt wingspan. the one i have on it now is a 14/6 or 14/8 cant remember wich one soz

I think a 14" prop is too much for a .75 size 2 stroke engine.
I pushed past the manufacturers recommendations with a 14x8 on my ST.90.
I would suggest 12x8 to 13x6
Here is tower hobbies page for their .75
http://www2.towerhobbies.com/cgi-bin...?&I=LXUR78&P=0

14" isn't to much...but try less pitch.