dkf1979,i put a 30cc homy on my sons balsa usa Dv111 1/4 scale.with engine it weighs 14.5 lbs with 83inch ws.it does loops and rolls and thats about it.you(WOULDNT) want to put one on a 27-28% aerobatic plane.it would fly but you wouldnt be happy.if you want to start into gassers cheap and have fun find aeronut and get a ryans rebel rtf.save the 30cc that was given to you and put it in say a balsa usa citabria.my sons 30cc has 2 rings and actually weighs about 6oz less than the single ring 25s.wher just using the stock flywheel and coil and i can hand start it on the third flip.good little engine,hold on to it.