RE: YS FZ110 Break in problem
I use the following procedure to tighten the prop nut and the lock nut, with a good wrench (about 6 inch long).
1. tighten the prop nut first, with left hand holding the prop blade and right the wrench, until the wrench can not move further
2. repeat the above step for the lock nut
Never had a problem.
I exclusively use TruTune's YS prop adaptors (prop nut and lock nut).