About the .60, i think you need to replace the glow plug. try an os #8 or a3 plug. the a3 is hotter, so try the #8 first. the only reason i reccomend the os plugs is they last forever. about that .78, it shouldn't really go above 12,000 rpm. two strokes can over rev, and it will ruin them. try putting on a bigger prop to absorb the energy