Usually I put in 2 to 2.5 oz tip weight in a AMA profile and it is 20+inches out on the outside wing and the engine is on the out side of the fuselage. With the .15 planes I'll put 3oz in and go from there because the wing is so much shorter and I loose a lot of leverage with the shorter span. I also use 7+ degrees of out thrust (sometimes 9-11 degrees) on the motor or engine as these planes need all the help they can get along with enough power to overcome the out thrust and tip weight. This is the beauty of flying your plane a lot, 20 to 30 or more times to learn what you can get away with, and just to get acquainted with your plane. So fly your plane and adjust from there, it sure is a nice looking plane. I think Ron Duly made one like yours, silver and blue and flew quite well.