I HAVE A SAITO 100 ON MINE SAME WIEGHT AS THE RECOMMENDED OS 70 AND IT IS NOT OVERPOWERED - IT IS NICE. YOU WILL FIND THAT THE .46 IS ONLY GOOD FOR SPORT FLYING, BUT YOU CA FORGET 3D. AND AT 5,000 FEET IT WILL BE SEVERLY LACKING. YOU WILL HAVE TO ALSO ADD NOSE WEIGHT TO GET IT TO BALANCE. WHY ADD NOSE WEIGHT WHEN YOU CAN INCREASE PERFORMANCE AND FUN WITH A BIGGER ENGINE. JUST MY OBSERVATIONS.