I have a 20 h.p. Kohler engine on my Rhino zero turn mower. Engine turns over and starts with no problems cold. When engine has reached operating temperature and you shut it down, it will not turn over to start. I have all valves adjusted to .005" and just installed a new starter and battery. I have to wait for the engine to cool off before it will turn over again. I can jump start with another car battery while the engine is hot but this is not working for me. Please any advice what could be going on. Thanks