I have been flying YS 1.20SF for a long time! My favorite prop is a 16 XC 8 APC, turning just at 9,000. The engine runs strong at this RPM and I like to idle at about 2200. It is not recommended to run the engine above this RPM. Did you get the owners manual (sheet) with the engine?
Good luck with it. Just remembered when I bought my first YS 1.20 1988. I still have it too. The fuel pump diaphram is the most suseptable part for trouble.
Bob
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