Well I started assembling mine this morning and am just about finished. I used an older K&B 6.5, (.40) which weighed about 3.5 ounces less than the OS. 46FX. I was able to put an 11 OZ. fuel tank in place of the 190cc. (7oz). I added a stearable tail wheel and it looks like I will still have to put the 1100 mil battery pack under the vertical fin just to get it to balance at 115/ 120 mm back! You would think they would get it straightened out by now!