Kirk,

... My personal + / -

+ : What stroker`s concern, perfect for F3A ( throttel management, brake , power curve ) stable when set properly , easy to operate , start etc. ( no problem day to day ), no specific weak parts.

- : YS quality control .... hmm ... ( Production control complete engine / individual parts , system and overview what modified parts concern ).... Or in other words ;" YS-Lottery" ... This problem have followed YS for many years ... Problems can occur without finding any specific unless you spend your time to investigate in tolerances etc...
They need to be taken care of, as a part of the hobby ( maintenance , operation ) at least if they shall work properly ... Those things have not change since older days ...

Well, i am still flying YS , soon electric :-)

Kjell OLav