RE: 50cc = 29 lbs thrust
milton - regardless of the findings, and whatever ensuing disputes occur.... I ** Really** like your method of documenting your tests on video. Well done... covers the basics very well...and your setup is pretty slick.
regardless of prop you choose, that seems like a pretty good 50cc class Chinese motor.
should work just fine for ya.
thanks for taking the effort to post good testing procedures!