Backfire

[Plmcrzy]

Any help would be greatly appreciated. I have a JD 145a with 218 hours. I have notice on last mowing that engine is backfiring through exhaust at full throttle. I have replaced air and fuel filter. And both plugs. Nothing has changed

 

[EngineMan]

It could be one of many things, maybe over rich (carburetion) and or a valve, can also be the ignition system.

 

[bertsmobile1]

Any help would be greatly appreciated. I have a JD 145a with 218 hours. I have notice on last mowing that engine is backfiring through exhaust at full throttle. I have replaced air and fuel filter. And both plugs. Nothing has changed

Backfiring through the exhaust is classic running too rich or spark too far retarded.
So you are checking that the air filters are clean.
You are checking the float height in the carb.
If no joy with new filter then slip off the flywheel nut/ bolt and check that the flywheel is in the right position. Keyway shoub be a full square.