btw, one thing that can really change the CG on a model is exactly where the engine is mounted. I'm not familiar with the ARF version of the 4* and what kind of motor mount it uses, but if you had to do some drilling, or if it's a clamp mount, did you move the engine as far back on the mounts as possible? Moving the something as heavy as the engine even 1/4" or less back can be huge, CG-wise. The 4* has those cheeks around the engine, but as long as you're using a small enough spinner, and the prop isn't hitting anything, you might be able to slide the engine back a bit. For that matter, cutting back on the cheeks to move the engine back removes excess wood up front as well...