I changed the spark plug and it's running worse than before

Take the plug out wire brush it and check the gap between the arm going over the ceramic white cone if its bent in to where theres no gap adjust back out to where there is put it on the metal frame where its still plugged into the wire but not screwed into the cylinder and turn it over if you see a spark in between the metal arm and the ceramic cone..thats blue! Not white or red or yellow.. Blue! Is what you wanna see screw it back in and it should be all good. Add some octane booster uf that doesnt work and floor it few times

If in fact changing the spark plug made any difference at all.*Make sure the replacement spark plug is the proper heat range for that particular engine. Should be in the 9s, Exp: xxx9x *Make sure the clearance between the ground electrode is .022-.024in if it is set any bigger the spark plug can miss any smaller and it can fowl. * DO NOT USE A WIRE BRUSH TO CLEAN A SPARK PLUG. it will leave Metallic scratches on the porcelain and cause Premature failure.