I was running my John Deere RX75 riding tractor, everythig was fine. Went out an hour later to start... mtor turns over fine but no spark to spark plug?

Hi,
This machine uses the Kawasaki FC290V 9HP engine which has both coil and igniter in the ignition system. Coil is M70276 and igniter is M73484. Most commonly the igniter fails though it is not usually to see them both fail at once. There may or may not be a single coil unit that will replace both, exists for some engines and not others.
Peace,
Clarke