... probably too late to answer this but... just in case it comes up in a search...
Kawasaki is using the new standard to rate its engines. I do not think Kholer has yet to start using them. This will result in them being almost the same rating. Typically Kawaski's dropped 3-4 HP when they started using the newer more accurate in real world methodology. But kudo's to them for doing so. But apples to apples your probably closer than you think.