I have a Kubota 2460G [gas] tractor that is 1 year old and diesels when shut off. It does it most of the time, even when it has cooled down before shutting off. Dealer tried to fix one time, but it did not help. Going into shop next week. Any ideas?
Get you a in line spark plug tester and hook up to the engine. See if the spark dies when you kill the switch. If the sparks does not but keeps up until the engine quits turning then that may be your problem. We had a Kohler that did that and it turn out to be a bad switch. The switch was shutting off the fuel solenoid but not killing the ignition so when you turned off the switch the engine kept running until the fuel in the intake was used up. About a 2 second lag. I do not even know if your engine has a fuel solenoid or not. Just a thought