Possibly finally looking at getting a new mower soon and trying to do some home work. Looking at a Gravely zero turn right now. Its offered with both of these engines. I think in a 52 inch cut the Kohler is a 25hp and the Kaw is a 23 hp. Things change so quick and names and series numbers change a lot also so its hard for the average guy to keep up. I know neither of these engines are top grade motors but we are only mowing a yard so I doubt it matters all that much. From what little I know I am leaning to the Kawasaki but that is only because a good friend had a Kaw FH series on a Yazoo that went over 1000 hours with no real trouble. I believe the FH series (which is no longer made) was a true commercial engine but I could be wrong. Looking for some opinions here on which you would pick and why.