lost power when I changed oil in my John Deer 145 Automatic tractor mower

Hello - to everybody. Hope all you people are doing well.
I have an 8-year old John Deer 145 Automatic tractor mower that suddenly lost power after
I recently changed the oil and filter. I checked the oil level , and it does not look like I overfilled. Would I
lose power if I did overfill? I plan on changing the spark plugs and fuel filter next.
Am I on the right track? I am not a mechanic, so I am guessing. It has a 22 Hp Briggs & Stratton Twin OVC engine.

Maybe its only running on one cylinder is the reason for the power loss?? A good start for a repair would be a set of new spark plugs.

When asking an engine question you should post the model number of the engine so we know what we are talking about. Your description is almost certainly incorrect. I would remove one spark plug wire at a time and see if it is only running on one cylinder. IF you find it is, remove the valve cover for the non operating cylinder and see if all is well in there, push rods in place and working for instance. Remove spark plug for that side and examine it and check if the piston for that side is going up and down.

Walt Conner .