After using mine for most of this year I discovered that the original wing tube (unfinished aluminum) was eating its way into the foam core by as much as 3.5 inches into the left wing and 1 inch into the right wing. I discovered this last time I went flying when the wing tube was way off center upon removal. Probably due to the vibration of the YS160DZ that is beating up the airframe pretty good. I am using an old Hyde Mount that was probably meant for the YS140.
Solution is that I made two circular balsa end caps 3/8"thick and inserted and sealed them into the wing holes at 9.25"depth giving about .25"play to the tube on either side.
GREAT airplane by the way!