Well I'm pretty convinced that the C of G is correct, although the plane was tail heavy before I used a 26cc petrol up front, this sorted it out and the C of G appeared correct to me, though as this is measured on the top wing it is only possible to use your fingers as a balance point which is not the best way, I will double check.

Also I will try the dive and see what happens, as it is it trims out in level flight, with the elevator in a nuetral position, no obvious up or down trim. One of the guys at the field did a similar test, took the plane real high, then a vertical dive, which from what I remember, it just went vertical down, with no deflection.

I'll let you know what happens.