It could be your carborator. Check that out. If your using Holley get rid of it. That is complete junk.
Your timing belt has probably worn out, or broken, and has jumped timing.
The engine is out of time. Have the engine timing checked. It can also be the plug wires are connected incorrectly.
First check for fire at any of the sparkplugs and if you have spark then check your fuel pressure and if its not within specs then replace the pump.
Double check, then triple check your firing order. Especially which distributor post is #1. Sounds like you're one off.
sounds like pluged catalitic converter or egr valve
Sounds like the timing is off.
Perhaps timing chain has jumped
sheared flywheel key. youtube has vids... type in mower cord backfires & you'll see instructions on how to fix it.
sounds like the clutch switch neeeds replacing or cleaning.
Timing is off.
Valve timing off, timing chain jump.
Your car backfires when you need a new transmission,or tune up. How do you know the difference? Simple...if your car backfires then wont start, or wont start and then backfires,you need a transmission. If it backfires, and then starts moments after, you need a tune-up. Glad to help...David
Your timing belt has probably worn out, or broken, and has jumped timing.
spark plug gap, gas/air mixture on carb.
The engine is out of time. Have the engine timing checked. It can also be the plug wires are connected incorrectly.
Possibly the firing order got messed up.
check fuil mixture