Actually... when they say .40... they mean .40. If they say .25 to .40, they don't mean .46 is approved. (they don't even mean .42...)

One of the worst habits being taught to beginners is the standard practice of putting oversize engines on models.

the beginner doesn't have the experience to know what plane its safe to "hop up" with a bigger engine.
the overpowered models tend to get flon at speeds they aren't designed for... and they snap the wing in flight. (Must have been a defective kit or ARF[:@]... bad design[:'(]... not my fault.)
The beginner has more problems keeping u wth the model in flight... training takes 2 to 20 times as long.
The airplane can be overweight from the hunk of metal on the nose... (and the corresponding lead in the tail to ballance it) making it have worse stall characteristics. (I thought the review said it was a forgiving plane... snaps like heck on final.[&:])

When you KNOW what your are doing... THEN you can go outside the recomended engine range. Till then, DON'T!