My John Deere lawn more just started backfiring through the carburetor. It’s a 20004 L 1 20. What would the possible causes for the backfiring be. I have change the plugs air filter fuel filter and oil.
What engine do you have on your mower ???? I'm betting on a Briggs twin cylinder...........
Model number from the engine is a must for us to help you out further.............
Let us know Mon Ami ~!~!
A bad cam, loose valve seat, bent pushrod , broken timing key , lean carb.
After the carb, start with the valves....... Pop the valve covers off and check your rods for a bent one, then while turning the engine over look at the rockers to see if the travel is the same........
Adjust the valves to 4 thou and 4 thou....