If your tractor cannot start, check your safety switches.
it might be the starter. have it checked out.
Obviously if it will not start, there IS something wrong with it.
The alternator,or starter might need replacing,or the battery might be dead.
it might be dead.
Might have a bad ignition control module or ignition coil. Good Luck!!
Usually the spark plugs or the timing.
you could have left the battery disconnected. or maybe you drained the battery, you might have to recharge it
if the injector is getting fuel, check for spark at the plugs, it might be the plug wires, bad plugs, rotor, pick up, or coil
You might the wrong driver, or it is not installed properly.
It is either getting no fuel or no spark.
catalytic converter?
you must have the wires on the wrong way.