I bought a 18hp kohler magnum for one of my 52"bunton hydros. the seller threw in a 61" deck which the magnum was turning for $50. He said it would spin it fine but the mower never had sulky on it. here is the question-the bunton now runs a 16hp v-twin vanguard with 52" deck pulling jungle wheels with my near 300lb but on them. On some of my yards the growth is thick and the mower will bog out and I have to nearly stop the mower to keep from killing the motor, thats why I got the magnum. So how much hp do you think I really need to turn the 61" deck? also how many rpms can you turn a magnum twin up to without destroying it. thanks in advance.