Is the plug on the left oily or sooty & is the right one white or tan?
Oily would be the rings or engine related. sooty would be poor spark, ignition problem.
White would be lean, carb problem. Tan would be normal, good.
Ignition. Is the battery good & fully charged? also, it would help to know if the ignition coils & spark plug wires are the stock originals. report back. that info can help in troubleshooting.
