Typical Kohler 25hp twin cylinder repair. Wonder if Kawasaki engine is a clone? Kohler has a repair kit for their engine. See if Kawaski has a kit also. Straight forward head gasket repair. Have done two Kohler engines so far. Don't forget to de-carbonized the piston tops, and cylinder heads. Good to remove valves and check seats also. Just about 5 hour job. The Kohler had a stub problem, kit had new studs, and replacement was suppose to cure the problem. Kit included head gaskets, intake and exhaust gaskets, studs, and new nuts if I remember correctly.