My John Deere LX 255 will not start. Getting no fire to spark plug. Was running fine, turned off would not start again. Checked fuel.

Hi,
Your machine has a Kohler Command single that "famously" shears flywheel keys. That would not keep it from having fire though. Only the ignition module or something in the harness will do that. Should be a plug on the left side of the engine that can be unplugged to check the viability of the module. Unplug it and check for fire again. None still, it is the module, fire and it is in the rest of the machine. Care must be taken to assure a good ground for the plug when trying it.
As a note: grasp engine and see if it can be wiggled side-to-side slightly in the frame. The engine mount bolts can loosen on that machine and disrupt the ground.
Peace,
Clarke