Z,
My engine is about centered in the fuse. It is 3/4" from the back of the spinner to the front edge of the fuse. The mounting holes are both about the same distance to the edge of the motor cut out in the fuse. I would have mounted it back a little more but with the carb in the back I didn't want the throttle linkage to be at too steep an angle or too short. I am not able to get a picture of it tonight, I'll try to get a couple tomorrow. When I measured the prop to the front edge of the wing, both sides were pretty close to the same, maybe 1/32 difference at most.I measured it with a steel rule so it's only as accurate as my eye! I had an OS 70 ultimate on it and it balanced with 1/4 ounce on the tail to get CG at 120mm. There were 2- 1/4 ounce weights glued to the outside edge of the right wing. It balance lateraly with the 70 on it, but when I checked again with the 80 Saito it was heavy to the right. I took both weights off and it balanced perfectly. The Saito seems much heavier than the Ultimate so I wasn't too worried about the lead in the tail. I figured that seemed to make sense with a heavier motor. I don't know the total weight of the completed plane.
Thanks,
Peter