LX178 John Deere 15hp v-twin liquid cool

I have a LX178 JD that will start right up but after 5 or 10 minutes it just shuts down. Wait 15 minutes and it will start up, but will shut down after getting hot. Radiator is full, fuel pump checked, filters changed, checked the pressure hole in the gas tank to make sure it is clean. What maybe causing the shut down? I can get it started without the mower on but it still will shut done after a minute or two. Seems that when it gets hot it just shuts down. Could it be the ignition coil, but I have two so it would need to be both coils at the same time. Any answers would help. Thanks

I know nothing about the liquid cooled engines but you could be low on oil and it is shutting down for that reason.

Run it with the air filter removed. When it dies, see if you can restart using starter fluid (ether). If it will fire and you can keep it running by spraying TINY amounts of starting fluid in the carburetor, you have a fuel problem. If it won't restart, you have an ignition problem.

That's one way.

Another is to have an ignition tester which you place along a plug wire. It will tell you if you have spark and they don't cost very much.