wolf, a 120 is almost the same spec and weight as a 108/91 we will fly it with great care and then slowly up the speed until we see if a problem shows, i have checked the spec carefully and we have flown the flans with both a saito100 and a os91fx so we are sure it can take more and its more on the vertical maneuvers we want the oompf. about the extra weight we had to add more than 70g in the nose with the 91fx so we are just compensating weight 60g is what the 120 weighs more and getting the extra.
ps nice pic of the ys