Something else too... Alot of the .40 size ARf's and kits are built to handle a .70 4 Stroke. You slide a .40 LA in it, and you'll have to add almost the equivelant of another engine in weight to even get clost to ballancing on the CG (although trainers are a different story). There's not that much difference in weight between a .70 FS and a G75. If you're going to do it anyways, you don't have to adjust the throttle, just put a smaller prop on it ... like 11x7 or so.