RE: YS 110 FZ Vent and Fuel Hook-up
Sounds like you have a streched crankshaft caused by over tightening the prop.
I have a streched shaft from a DZ on my bench at the moment.
Borrow another engine or get a bolt of the same thread pitch and hold the two threads together,
you will soon see if the threads are streched.
I had to teach my son on how to use a tension wrench as he has not yet developed the feel for judging tensions yet.
Will Crossman
Down under