Originally Posted by JimQ
Don't let the HP figures fool you. The 31hp Kawi is a lot more engine that the 30 hp Kohler. There is a substantial real-world power difference. The Kawi is the stronger of the two by far. The 30hp Kohler is a 747cc engine while the Kawi is an 852cc engine.
I used the 30hp Kohler on a 66" Lazer Z and it's pretty weak. The 31hp Vanguard that I've used on a 60" Lazer Z XS which would be slightly larger than the 31hp Kawasaki, has tons of power.