I am relatively new to gassers but i did have a MUCH more experienced club member balance my prop. This guy owns a few 30%+ planes one of which was a 36% (i think) Katana that was wrecked last year due to unknown reasons. He is the best in our club. I'm sure that prop balance is not the problem. Its not the spinner either because i dont have one on this plane ( its a GBY with just a nut).