I am a YS user from China, what I think the YAMADA need to be changed is ,making the engine electricize (like EFI, mixture and vlave control under the automation ) rather making the boxer or sth like contra etc..
More and more people start flying the jet model due to their easy start and user-friendly feature,
For some beginer, how to install a YS engine , and start it or test it still a series big problems, if the YS engine can start or run as easy as a car(or motor cycle) engine, I think it will go further in the RC field.
Just personal oppinion.
Best,