i have a brison 2.4 in a midwest extra at about 16 lbs. I use a zinger 20x8 prop, i suppose there are better props but it was available. Anyway this combo flies very nice and will hover at basically 7-8 throtle. If you want to do waterfalls and torque rolls you will want to get a bigger engine. If not the 2.4 should please you. A little more on props, Ive run a mejlick 19x10 and a forte' 18x10 which ohio rc, a former distributer of brison recomended. The zinger 20x8 WAY outperformed these other props. A menz 20x8 would be what I would try if I had one laying around. Something else to maybe consider. My midwest will not allow a 22"prop as far as ground clearance so the gp extra could be the same way, dont know? For my flying style I would want 50cc in this plane instead of 40 as I want to be able to do knife edge loops,torque rolls, well atleast try anyway.