i havent fooled with 2 strokes for years but i would say an OS 120 would be about as close as you could get in a 2 stroke (dont quote me) you wold be better of asking that to someone up to date on them... the only thing is the 2 stroke would be more weight. something that would turn a 17X4W would be best because an 18 looked like tight clearance on diled pictures.. some people also say the evolution 100 is a good strong motor but again i have never run one so i coudnt say