Plain BS. Only a very few parts are not available from Kawasaki. Most Kawasaki engines I repair are on JD equipment and I don't buy the parts from JD. Matter of fact I got a Kawasaki fuel pump and carburetor parts coming in Wednesday for a engine on the JD LX178 from my Kawasaki distributor.
I got the head and valves for the engine on the 737 I repaired a few weeks ago. JD wanted $226.91 for it but I got it through my distributor for $174 So I actually sold the head to customer for $195. Made a decent profit and saved the customer money too. Of course there were valves, stems seals, and gaskets are not part of the $195 but I pass along similar savings to customer.
OP, No problem here looking up that engine. Can you put together a list of parts you are wanting?, and I can get the Kawasaki PNs for you. I know you need the head gasket, crankcase cover gasket (oil pan) and the two crankshaft oil seals but what else are you wanting? Are you actually wantng the crankshaft, rod, and piston?