N1EDM - thanks for the words of advice and encouragement. i have broken in over 10 engines and flown over a dozen so i'm okay in terms of knowing what to look for. naturally having had so many planes doesn't really mean that you are any better at tuning an engine than someone who is just starting, but... i think i am okay. i just think my 75 was a dud. or rather is a dud... with the 30%, it runs okay... but no where enough power for its gas consumption.