i had a limbo once..........

it had a OS 35fp and it would hover quite easliy. i couldent but i eventually got the hang of it and promptly lost it in a mid air.

props: APC 10x4, 10x5, 11x3, 11x4 and a bolly 10.5x4
ive seen 13x4 props on these engines and i personnally think this is way OTT