I am used to my small high revving engines turning 10" props to 15,000 rpm. Just 9000 rpm to me is "unfamiliar". I guess like my four strokes I will be going with higher pitch props. So in your opinion was the Irvine a good running reliable engine worth keeping like all my others? Its hard for me to believe the 1.50 is underpowered when all my other Irvines (I have quite a few) are so excellent. Is 9000 a good static rpm to prop for with this engine? I see the 1.20 AX is listed with a 9000 rpm max useable rpm.