RE: YS115FZ-S when/where available??
YS115S has 30.4mm bore with 25.8mm stroke. 730grams (7 grams more than 110S)
YS110S has 30.4mm bore with 24.8mm stroke.
115S will probably sell for very similar price of 110S.
Not sure how many parts are different, but it may be possible to convert the 110S to 115S.
Not really sure why YS went to longer stroke. Single cylinder with longer stroke especially 4 stroke may vibrate more. Isn't it?