ORIGINAL: STG
Did you ever run the bigger 19" prop on the YS. Sometimes just a step up in prop Dia seems to help a lot for everything. I have a 60" FL330 and going from a 15 to 16 prop makes everthing better.
Yes I ran a apc 19x8w and the 3w 19x8. I settled on the 18x8msc because the spool up was slightly faster
Al