I don't know what kind of conversion table you came up with and I don't really see how they could even convert cc to hp,just like cubic inches to hp,the 2 aren't related.B&S used cc for awhile on a few of their engines,I believe a 5hp B&S engine is 206cc,that's just off the top of my head so,I'm not positive that I have that correct.At the same time a 250cc,2 stroke engine puts out about 30 or 35 hp stock.