yeah ... that's what I like best about SPADS. The thing about most ARFs is that usually, anything lighter than the largest recommended engine will require moving everything as far forward as you can get it. That means you should have to shift almost 5 ounces toward the front. Here's another question ... When you're ballancing the plane, you're doing it upside down ... right? Also, check the total weight of the plane. With the 46AX, it should come in at about 5 3/4 pounds.