How to fix a John Deere X520 from back firing

[kjackson4]

Hello my name is Kent Jackson I am new to this site.I just wanted to tell any one who might have the same problem that I had how I fixed my John Deere X520 from all it wanted to do was to back fire.My lawn tractor all I could get out of it was when you went to try and start it all it would do was back fire through the carburetor.I tried everything to fix it This all started last year in the spring after it sat over the winter.The way I finally fixed it was to unhook the kill wire from the ignition coil I unhooked the kill wire to the number 2 cylinder which also unhooks the number 1 cylinder and the way you shut off the engine is by just turning the key off and the electronic fuel solenoid shuts the fuel off and it kills the engine.Thank You

 

[Spiros]

Welcome to the forum Kent. And, well done.

 

[jgayman]

That sounds like a good work around but whatever the problem is (was) it probably still exists. Those individual kill wires typically have diodes in them to prevent the two ignition coils from interacting. If one of the diodes is bad or intermittent it can cause the coils to fire out of time and create the backfiring situation you were experiencing.