Posted for vtailjeff@aol.com:

Fred,
 
 Thanks for the excerpt from John's article but it is actually BELOW 60-65%
....I am sure it was a slip of the keyboard... just wanted to make sure it was
clear..
 
 Best Regards,
 
 Jeff
 
 Above about 60-65% you can set mixture with impunity and do no damage
according to his reports.  He does show you can lean at 80% power with this
engine, but as I recall it must be 75-80F lean of peak.